1
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Wieringa N, Droge STJ, Ter Laak TL, Nair AAK, Walker K, Verdonschot PFM, Kraak MHS. Combining Passive Sampling and Dosing to Unravel the Contribution of Hydrophobic Organic Contaminants to Sediment Ecotoxicity. Environ Sci Technol 2024; 58:269-279. [PMID: 38153417 PMCID: PMC10785821 DOI: 10.1021/acs.est.3c07807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/10/2023] [Accepted: 12/11/2023] [Indexed: 12/29/2023]
Abstract
Contaminated sediments are ubiquitous repositories of pollutants and cause substantial environmental risks. Results of sediment bioassays remain difficult to interpret, however, as observed effects may be caused by a variety of (un)known stressors. This study aimed therefore to isolate the effects of hydrophobic organic contaminants from other (non)chemical stressors present in contaminated sediments, by employing a newly developed passive sampling-passive dosing (PSPD) test. The results showed that equilibrium partitioning between pesticides or polyaromatic hydrocarbons (PAHs) in contaminated sediments and a silicone rubber (SR) passive sampler was achieved after 1-3 days. Chlorpyrifos concentrations in pore water of spiked sediment matched very well with concentrations released from the SR into an aqueous test medium, showing that SR can serve as a passive dosing device. Subjecting the 96 h PSPD laboratory bioassay with nonbiting midge (Chironomus riparius) larvae to field-collected sediments showed that at two locations, concentrations of the hydrophobic organic contaminant mixtures were high enough to affect the test organisms. In conclusion, the developed PSPD test was able to isolate the effects of hydrophobic organic contaminants and provides a promising simplified building block for a suite of PSPD tests that after further validation could be used to unravel the contribution of hydrophobic organic chemicals to sediment ecotoxicity.
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Affiliation(s)
- Nienke Wieringa
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Steven T. J. Droge
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
- Wageningen
Environmental Research, Wageningen University
and Research, P.O. Box 47, 6700 AA Wageningen, The Netherlands
| | - Thomas L. Ter Laak
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
- KWR
Water Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, The Netherlands
| | - Aishwarya A. K. Nair
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Kelsey Walker
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Piet F. M. Verdonschot
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
- Wageningen
Environmental Research, Wageningen University
and Research, P.O. Box 47, 6700 AA Wageningen, The Netherlands
| | - Michiel H. S. Kraak
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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2
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McLachlan MS, Ebert A, Armitage JM, Arnot JA, Droge STJ. A framework for understanding the bioconcentration of surfactants in fish. Environ Sci Process Impacts 2023; 25:1238-1251. [PMID: 37350243 DOI: 10.1039/d3em00070b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Surfactants are a class of chemicals released in large quantities to water, and therefore bioconcentration in fish is an important component of their safety assessment. Their structural diversity, which encompasses nonionic, anionic, cationic and zwitterionic molecules with a broad range of lipophilicity, makes their evaluation challenging. A strong influence of environmental pH adds a further layer of complexity to their bioconcentration assessment. Here we present a framework that penetrates this complexity. Using simple equations derived from current understanding of the relevant underlying processes, we plot the key bioconcentration parameters (uptake rate constant, elimination rate constant and bioconcentration factor) as a function of its membrane lipid/water distribution ratio and the neutral fraction of the chemical in water at pH 8.1 and at pH 6.1. On this chemical space plot, we indicate boundaries at which four resistance terms (perfusion with water, transcellular, paracellular, and perfusion with blood) limit transport of surfactants across the gills. We then show that the bioconcentration parameters predicted by this framework align well with in vivo measurements of anionic, cationic and nonionic surfactants in fish. In doing so, we demonstrate how the framework can be used to explore expected differences in bioconcentration behavior within a given sub-class of surfactants, to assess how pH will influence bioconcentration, to identify the underlying processes governing bioconcentration of a particular surfactant, and to discover knowledge gaps that require further research. This framework for amphiphilic chemicals may function as a template for improved understanding of the accumulation potential of other ionizable chemicals of environmental concern, such as pharmaceuticals or dyes.
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Affiliation(s)
- Michael S McLachlan
- Department of Environmental Science, Stockholm University, 106 91 Stockholm, Sweden.
| | - Andrea Ebert
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research - UFZ, D-04318 Leipzig, Germany
| | - James M Armitage
- AES Armitage Environmental Sciences, Inc., Ottawa, Ontario K1L 8C3, Canada
| | - Jon A Arnot
- ARC Arnot Research and Consulting Inc., Toronto, Ontario M4M 1W4, Canada
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Steven T J Droge
- Wageningen Environmental Research, Team Environmental Risk Assessment, 6700 AA Wageningen, The Netherlands
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3
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Droge STJ, Hodges G, Bonnell M, Gutsell S, Roberts J, Teixeira A, Barrett EL. Using membrane-water partition coefficients in a critical membrane burden approach to aid the identification of neutral and ionizable chemicals that induce acute toxicity below narcosis levels. Environ Sci Process Impacts 2023; 25:621-647. [PMID: 36779707 DOI: 10.1039/d2em00391k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The risk assessment of thousands of chemicals used in our society benefits from adequate grouping of chemicals based on the mode and mechanism of toxic action (MoA). We measure the phospholipid membrane-water distribution ratio (DMLW) using a chromatographic assay (IAM-HPLC) for 121 neutral and ionized organic chemicals and screen other methods to derive DMLW. We use IAM-HPLC based DMLW as a chemical property to distinguish between baseline narcosis and specific MoA, for reported acute toxicity endpoints on two separate sets of chemicals. The first set comprised 94 chemicals of US EPA's acute fish toxicity database: 47 categorized as narcosis MoA, 27 with specific MoA, and 20 predominantly ionic chemicals with mostly unknown MoA. The narcosis MoA chemicals clustered around the median narcosis critical membrane burden (CMBnarc) of 140 mmol kg-1 lipid, with a lower limit of 14 mmol kg-1 lipid, including all chemicals labelled Narcosis_I and Narcosis_II. This maximum 'toxic ratio' (TR) between CMBnarc and the lower limit narcosis endpoint is thus 10. For 23/28 specific MoA chemicals a TR >10 was derived, indicative of a specific adverse effect pathway related to acute toxicity. For 10/12 cations categorized as "unsure amines", the TR <10 suggests that these affect fish via narcosis MoA. The second set comprised 29 herbicides, including 17 dissociated acids, and evaluated the TR for acute toxic effect concentrations to likely sensitive aquatic plant species (green algae and macrophytes Lemna and Myriophyllum), and non-target animal species (invertebrates and fish). For 21/29 herbicides, a TR >10 indicated a specific toxic mode of action other than narcosis for at least one of these aquatic primary producers. Fish and invertebrate TRs were mostly <10, particularly for neutral herbicides, but for acidic herbicides a TR >10 indicated specific adverse effects in non-target animals. The established critical membrane approach to derive the TR provides for useful contribution to the weight of evidence to bin a chemical as having a narcosis MoA or less likely to have acute toxicity caused by a more specific adverse effect pathway. After proper calibration, the chromatographic assay provides consistent and efficient experimental input for both neutral and ionizable chemicals to this approach.
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Affiliation(s)
- Steven T J Droge
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED), Universiteit van Amsterdam (UvA), Science Park 904, 1098XH Amsterdam, The Netherlands.
| | - Geoff Hodges
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
| | - Mark Bonnell
- Environment and Climate Change Canada, Ecological Assessment Division, Science and Risk Assessment Directorate, Gatineau, Quebec, Canada
| | - Steve Gutsell
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
| | - Jayne Roberts
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
| | - Alexandre Teixeira
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
| | - Elin L Barrett
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
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4
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Wieringa N, Droge STJ, Bakker AM, Melkert RA, Prast BJ, Verdonschot PFM, Kraak MHS. Enlarging the Arsenal of Test Species for Sediment Quality Assessment. Bull Environ Contam Toxicol 2023; 110:55. [PMID: 36790477 PMCID: PMC9931774 DOI: 10.1007/s00128-023-03691-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/12/2023] [Indexed: 06/18/2023]
Abstract
Since only a few standard benthic test species are available for sediment quality, our study aimed to employ multiple test species representing different sensitivity categories in the quality assessment of contaminated sediments. To this end three macroinvertebrate species, Sericostoma personatum (caddisfly, sensitivity category 10), Asellus aquaticus (isopod, category 3) and Chironomus riparius (chironomid, category 2), were exposed to sediments originating from various contamination sources in whole sediment bioassays using intact sediment cores. The agricultural sediment caused insect mortality, the agricultural and urban sediment caused isopod growth reduction and the urban and Wastewater Treatment Plant (WWTP) sediment affected chironomid emergence time. It is concluded that the arsenal of standard species can be successfully expanded by non-standard species, reducing over- or underestimation of the risks of contaminated sediments.
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Affiliation(s)
- N Wieringa
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
| | - S T J Droge
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
- Wageningen Environmental Research, Wageningen University and Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - A M Bakker
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
- Wageningen Environmental Research, Wageningen University and Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - R A Melkert
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - B J Prast
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - P F M Verdonschot
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
- Wageningen Environmental Research, Wageningen University and Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - M H S Kraak
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
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5
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Sigmund G, Arp HPH, Aumeier BM, Bucheli TD, Chefetz B, Chen W, Droge STJ, Endo S, Escher BI, Hale SE, Hofmann T, Pignatello J, Reemtsma T, Schmidt TC, Schönsee CD, Scheringer M. Correction to "Sorption and Mobility of Charged Organic Compounds: How to Confront and Overcome Limitations in Their Assessment". Environ Sci Technol 2022; 56:11093. [PMID: 35856257 PMCID: PMC9352312 DOI: 10.1021/acs.est.2c05051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Indexed: 06/15/2023]
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6
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Ribbenstedt A, Armitage JM, Günther F, Arnot JA, Droge STJ, McLachlan MS. In Vivo Bioconcentration of 10 Anionic Surfactants in Rainbow Trout Explained by In Vitro Data on Partitioning and S9 Clearance. Environ Sci Technol 2022; 56:6305-6314. [PMID: 35467837 PMCID: PMC9118553 DOI: 10.1021/acs.est.1c05543] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Bioconcentration factors (BCFs) in rainbow trout were measured for 10 anionic surfactants with a range of alkyl chain lengths and different polar head groups. The BCFs ranged from 0.04 L kg-1 ww (for C10SO3) to 1370 L kg-1 ww (C16SO3). There was a strong correlation between the log BCF and log membrane lipid-water distribution ratio (DMLW, r2 = 0.96), and biotransformation was identified as the dominant elimination mechanism. The strong positive influence of DMLW on BCF was attributed to two phenomena: (i) increased partitioning from water into the epithelial membrane of the gill, leading to more rapid diffusion across this barrier and more rapid uptake, and (ii) increased sequestration of the surfactant body burden into membranes and other body tissues, resulting in lower freely dissolved concentrations available for biotransformation. Estimated whole-body in vivo biotransformation rate constants kB-BCF are within a factor three of rate constants estimated from S9 in vitro assays for six of the eight test chemicals for which kB-BCF could be determined. A model-based assessment indicated that the hepatic clearance rate of freely dissolved chemicals was similar for the studied surfactants. The dataset will be useful for evaluation of in silico and in vitro methods to assess bioaccumulation.
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Affiliation(s)
- Anton Ribbenstedt
- Department
of Environmental Science, Stockholm University, 106 91 Stockholm, Sweden
| | - James M. Armitage
- AES
Armitage Environmental Sciences, Inc., Ottawa, Ontario K1L 8C3, Canada
| | - Felix Günther
- Department
of Mathematics, Stockholm University, 106 91 Stockholm, Sweden
| | - Jon A. Arnot
- ARC
Arnot Research and Consulting Inc., Toronto, Ontario M4M 1W4, Canada
- Department
of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Steven T. J. Droge
- Institute
for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, 1090 GE Amsterdam, The Netherlands
| | - Michael S. McLachlan
- Department
of Environmental Science, Stockholm University, 106 91 Stockholm, Sweden
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7
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Sigmund G, Arp HPH, Aumeier BM, Bucheli TD, Chefetz B, Chen W, Droge STJ, Endo S, Escher BI, Hale SE, Hofmann T, Pignatello J, Reemtsma T, Schmidt TC, Schönsee CD, Scheringer M. Sorption and Mobility of Charged Organic Compounds: How to Confront and Overcome Limitations in Their Assessment. Environ Sci Technol 2022; 56:4702-4710. [PMID: 35353522 PMCID: PMC9022425 DOI: 10.1021/acs.est.2c00570] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Permanently charged and ionizable organic compounds (IOC) are a large and diverse group of compounds belonging to many contaminant classes, including pharmaceuticals, pesticides, industrial chemicals, and natural toxins. Sorption and mobility of IOCs are distinctively different from those of neutral compounds. Due to electrostatic interactions with natural sorbents, existing concepts for describing neutral organic contaminant sorption, and by extension mobility, are inadequate for IOC. Predictive models developed for neutral compounds are based on octanol-water partitioning of compounds (Kow) and organic-carbon content of soil/sediment, which is used to normalize sorption measurements (KOC). We revisit those concepts and their translation to IOC (Dow and DOC) and discuss compound and soil properties determining sorption of IOC under water saturated conditions. Highlighting possible complementary and/or alternative approaches to better assess IOC mobility, we discuss implications on their regulation and risk assessment. The development of better models for IOC mobility needs consistent and reliable sorption measurements at well-defined chemical conditions in natural porewater, better IOC-, as well as sorbent characterization. Such models should be complemented by monitoring data from the natural environment. The state of knowledge presented here may guide urgently needed future investigations in this field for researchers, engineers, and regulators.
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Affiliation(s)
- Gabriel Sigmund
- Department
of Environmental Geosciences, Centre for Microbiology and Environmental
Systems Science, University of Vienna, 1090 Wien, Austria
| | - Hans Peter H. Arp
- Norwegian
Geotechnical Institute (NGI), P.O. Box 3930 Ullevaal Stadion, N-0806 Oslo, Norway
- Norwegian
University of Science and Technology (NTNU), NO-7491 Trondheim, Norway
| | - Benedikt M. Aumeier
- RWTH
Aachen University, Institute of Environmental Engineering, Mies-van-der-Rohe Straße 1, 52074 Aachen, Germany
| | | | - Benny Chefetz
- Department
of Soil and Water Sciences, Institute of Environmental Sciences; Faculty
of Agriculture, Food and Environment, The
Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel
| | - Wei Chen
- College
of Environmental Science and Engineering, Ministry of Education Key
Laboratory of Pollution Processes and Environmental Criteria, Tianjin
Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, P. R. China
| | - Steven T. J. Droge
- Wageningen
Environmental Research, Wageningen University
and Research, P.O. Box 47, 6700AA, Wageningen, Netherlands
| | - Satoshi Endo
- Health
and Environmental Risk Division, National
Institute for Environmental Studies (NIES), Onogawa 16-2, 305-8506 Tsukuba, Ibaraki Japan
| | - Beate I. Escher
- Department
of Cell Toxicology, Helmholtz Centre for
Environmental Research − UFZ, Permoser Strasse 15, DE-04318 Leipzig, Germany
- Environmental
Toxicology, Center for Applied Geoscience, Eberhard Karls University Tübingen, Schnarrenbergstr. 94-96, DE-72076 Tübingen, Germany
| | - Sarah E. Hale
- Norwegian
Geotechnical Institute (NGI), P.O. Box 3930 Ullevaal Stadion, N-0806 Oslo, Norway
| | - Thilo Hofmann
- Department
of Environmental Geosciences, Centre for Microbiology and Environmental
Systems Science, University of Vienna, 1090 Wien, Austria
| | - Joseph Pignatello
- Department
of Environmental Sciences, The Connecticut
Agricultural Experiment Station, New Haven; 123 Huntington St., New Haven, Connecticut 06504-1106, United States
| | - Thorsten Reemtsma
- Department
of Analytical Chemistry, Helmholtz Centre
for Environmental Research − UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
- Institute for Analytical Chemistry, University
of Leipzig, Linnéstrasse
3, 04103 Leipzig, Germany
| | - Torsten C. Schmidt
- Instrumental
Analytical Chemistry and Centre for Water and Environmental Research
(ZWU), University of Duisburg-Essen, Universitätsstrasse 5, 45141 Essen, Germany
| | | | - Martin Scheringer
- RECETOX, Masaryk University, 625 00 Brno, Czech Republic
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, 8092 Zürich, Switzerland
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8
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Droge STJ, Scherpenisse P, Arnot JA, Armitage JM, McLachlan MS, Ohe PCVD, Hodges G. Screening the baseline fish bioconcentration factor of various types of surfactants using phospholipid binding data. Environ Sci Process Impacts 2021; 23:1930-1948. [PMID: 34787154 DOI: 10.1039/d1em00327e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Fish bioconcentration factors (BCFs) are commonly used in chemical hazard and risk assessment. For neutral organic chemicals BCFs are positively correlated with the octanol-water partition ratio (KOW), but KOW is not a reliable parameter for surfactants. Membrane lipid-water distribution ratios (DMLW) can be accurately measured for all kinds of surfactants, using phospholipid-based sorbents. This study first demonstrates that DMLW values for ionic surfactants are more than 100 000 times higher than the partition ratio to fish-oil, representing neutral storage lipid. A non-ionic alcohol ethoxylate surfactant showed almost equal affinity for both lipid types. Accordingly, a baseline screening BCF value for surfactants (BCFbaseline) can be approximated for ionic surfactants by multiplying DMLW by the phospholipid fraction in tissue, and for non-ionic surfactants by multiplying DMLW by the total lipid fraction. We measured DMLW values for surfactant structures, including linear and branched alkylbenzenesulfonates, an alkylsulfoacetate and an alkylethersulfate, bis(2-ethylhexyl)-surfactants (e.g., docusate), zwitterionic alkylbetaines and alkylamine-oxides, and a polyprotic diamine. Together with sixty previously published DMLW values for surfactants, structure-activity relationships were derived to elucidate the influence of surfactant specific molecular features on DMLW. For 23 surfactant types, we established the alkyl chain length at which BCFbaseline would exceed the EU REACH bioaccumulation (B) threshold of 2000 L kg-1, and would therefore require higher tier assessments to further refine the BCF estimate. Finally, the derived BCFbaseline are compared with measured literature in vivo BCF data where available, suggesting that refinements, most notably reliable estimates of biotransformation rates, are needed for most surfactant types.
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Affiliation(s)
- Steven T J Droge
- Institute for Biodiversity and Ecosystem Dynamics, Department Freshwater and Marine Ecology, University of Amsterdam, The Netherlands.
| | - Peter Scherpenisse
- Institute for Risk Assessment Sciences, Utrecht University, The Netherlands
| | - Jon A Arnot
- ARC Arnot Research and Consulting, Toronto, Ontario, Canada
| | | | | | | | - Geoff Hodges
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, UK
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9
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Kierkegaard A, Sundbom M, Yuan B, Armitage JM, Arnot JA, Droge STJ, McLachlan MS. Bioconcentration of Several Series of Cationic Surfactants in Rainbow Trout. Environ Sci Technol 2021; 55:8888-8897. [PMID: 34133133 PMCID: PMC8277129 DOI: 10.1021/acs.est.1c02063] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/22/2021] [Accepted: 06/07/2021] [Indexed: 05/03/2023]
Abstract
Cationic surfactants have a strong affinity to sorb to phospholipid membranes and thus possess an inherent potential to bioaccumulate, but there are few measurements of bioconcentration in fish. We measured the bioconcentration of 10 alkylamines plus two quaternary ammonium compounds in juvenile rainbow trout at pH 7.6, and repeated the measurements at pH 6.2 for 6 of these surfactants. The BCF of the amines with chain lengths ≤ C14 was positively correlated with chain length, increasing ∼0.5 log units per carbon. Their BCF was also pH dependent and approximately proportional to the neutral fraction of the amine in the water. The BCFs of the quaternary ammonium compounds showed no pH dependence and were >2 orders of magnitude less than for amines of the same chain length at pH 7.6. This indicates that systemic uptake of permanently charged cationic surfactants is limited. The behavior of the quaternary ammonium compounds and the two C16 amines studied was consistent with previous observations that these surfactants accumulate primarily to the gills and external surfaces of the fish. At pH 7.6 the BCF exceeded 2000 L kg-1 for 4 amines with chains ≥ C13, showing that bioconcentration can be considerable for some longer chained cationic surfactants.
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Affiliation(s)
- Amelie Kierkegaard
- Department
of Environmental Science, Stockholm University, Stockholm SE-106 91, Sweden
| | - Marcus Sundbom
- Department
of Environmental Science, Stockholm University, Stockholm SE-106 91, Sweden
| | - Bo Yuan
- Department
of Environmental Science, Stockholm University, Stockholm SE-106 91, Sweden
| | - James M. Armitage
- AES
Armitage Environmental Sciences, Incorporated, Ottawa, Ontario K1L 8C3, Canada
| | - Jon A. Arnot
- ARC
Arnot Research and Consulting, Incorporated, Toronto, Ontario M4M 1W4, Canada
- Department
of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario MM1C 1A4, Canada
| | - Steven T. J. Droge
- Institute
for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam 1090 GE, The Netherlands
- Dutch
Board
for the Authorisation of Plant Protection Products and Biocides (Ctgb), Ede 6717 LL, The Netherlands
| | - Michael S. McLachlan
- Department
of Environmental Science, Stockholm University, Stockholm SE-106 91, Sweden
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10
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Timmer N, Gore D, Sanders D, Gouin T, Droge STJ. Application of seven different clay types in sorbent-modified biodegradability studies with cationic biocides. Chemosphere 2020; 245:125643. [PMID: 31877460 DOI: 10.1016/j.chemosphere.2019.125643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 06/10/2023]
Abstract
The cationic surfactants cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC) can exert inhibitory effects on micro-organisms responsible for their biodegradation. However, under environmentally relevant exposure scenarios the presence of and sorption to organic and inorganic matter can lead to significant reduction of inhibitory effects. In our studies we investigated silica gel and seven clays as inert sorbents to mitigate these inhibitory effects in a 28 day manometric respirometry biodegradation test. CTAB was not inhibitory to the used inoculum, but we did observe that seven out of eight sorbents increased maximum attainable biodegradation, and four out of eight decreased the lag phase. The strongly inhibitory effect of CPC was successfully mitigated by most sorbents, with five out of eight allowing >50% biodegradation within 28 days. Results further indicate that bioaccessibility of the sorbed fractions in the stirred manometric test systems was higher than in calmly shaken headspace test systems. Bioaccessibility might also be limited depending on characteristics of test chemical and sorbent type, with montmorillonite and bentonite apparently providing the lowest level of bioaccessibility with CPC. Clay sorbents can thus be used as environmentally relevant sorbents to mitigate potential inhibitory effects of test chemicals, but factors that impede bioaccessibility should be considered. In addition to apparently increased bioaccessibility due to stirring, the automated manometric respirometry test systems give valuable and highly cost-effective insights into lag phase and biodegradation kinetics; information that is especially relevant for test chemicals of gradual biodegradability.
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Affiliation(s)
- Niels Timmer
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, 3508 TD, the Netherlands; Department Discovery and Environmental Sciences, Charles River Laboratories Den Bosch BV, 's-Hertogenbosch, 5231 DD, the Netherlands
| | - David Gore
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, MK44 1LQ, Bedfordshire, UK
| | - David Sanders
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, MK44 1LQ, Bedfordshire, UK
| | - Todd Gouin
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, MK44 1LQ, Bedfordshire, UK
| | - Steven T J Droge
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, 3508 TD, the Netherlands; Department Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE, Amsterdam, the Netherlands.
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11
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de Baat ML, Wieringa N, Droge STJ, van Hall BG, van der Meer F, Kraak MHS. Smarter Sediment Screening: Effect-Based Quality Assessment, Chemical Profiling, and Risk Identification. Environ Sci Technol 2019; 53:14479-14488. [PMID: 31714076 PMCID: PMC6921687 DOI: 10.1021/acs.est.9b02732] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 11/01/2019] [Accepted: 11/12/2019] [Indexed: 05/27/2023]
Abstract
Sediments play an essential role in the functioning of aquatic ecosystems but simultaneously retain harmful compounds. However, sediment quality assessment methods that consider the risks caused by the combined action of all sediment-associated contaminants to benthic biota are still underrepresented in water quality assessment strategies. Significant advancements have been made in the application of effect-based methods, but methodological improvements can still advance sediment risk assessment. The present study aimed to explore such improvements by integrating effect-monitoring and chemical profiling of sediment contamination. To this end, 28 day life cycle bioassays with Chironomus riparius using intact whole sediment cores from contaminated sites were performed in tandem with explorative chemical profiling of bioavailable concentrations of groups of legacy and emerging sediment contaminants to investigate ecotoxicological risks to benthic biota. All contaminated sediments caused effects on the resilient midge C. riparius, stressing that sediment contamination is ubiquitous and potentially harmful to aquatic ecosystems. However, bioassay responses were not in line with any of the calculated toxicity indices, suggesting that toxicity was caused by unmeasured compounds. Hence, this study underlines the relevance of effect-based sediment quality assessment and provides smarter ways to do so.
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Affiliation(s)
- Milo L. de Baat
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Nienke Wieringa
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Steven T. J. Droge
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Bart G. van Hall
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | | | - Michiel H. S. Kraak
- Department
of Freshwater and Marine Ecology (FAME), Institute for Biodiversity
and Ecosystem Dynamics (IBED), University
of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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12
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Timmer N, Gore D, Sanders D, Gouin T, Droge STJ. Sorbent-modified biodegradation studies of the biocidal cationic surfactant cetylpyridinium chloride. Ecotoxicol Environ Saf 2019; 182:109417. [PMID: 31302333 DOI: 10.1016/j.ecoenv.2019.109417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 06/29/2019] [Accepted: 07/03/2019] [Indexed: 06/10/2023]
Abstract
Biodegradability studies for the cationic surfactant cetylpyridinium chloride (CPC) are hampered by inhibitory effects on inoculum at prescribed test concentrations (10-20 mg organic carbon/L). In this study, we used 14C labeled CPC in the 28 d Headspace Test (OECD 310) and demonstrated that CPC was readily biodegradable (10->60% mineralization within a 10 day window) at test concentrations 0.006-0.3 mg/L with CPC as single substrate. Biodegradation efficiency was comparable over this concentration range. CPC inhibited degradation at 1 mg/L and completely suppressed inoculum activity at 3 mg/L. In an extensive sorbent modified biodegradation study we evaluated the balance between CPC bioaccessibility and toxicity. A non-inhibitory concentration of 0.1 mg/L CPC was readily biodegradable with 83% sorbed to SiO2, while biodegradation was slower when 96% was sorbed. SiO2 mitigated inhibitory effects of 1 mg/L CPC, reaching >60% biodegradation within 28 d; inhibitory effects were also mitigated by addition of commercial clay powder (illite) but this was primarily reflected by a reduced lag phase. At 10 mg/L CPC SiO2 was still able to mitigate inhibitory effects, but bioaccessibility seemed limited as only 20% biodegradation was reached. Illite limited bioaccessibility more strongly and was not able to sustain biodegradation at 10 mg/L CPC.
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Affiliation(s)
- Niels Timmer
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, 3508, TD, the Netherlands
| | - David Gore
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, MK44 1LQ. Bedfordshire, UK
| | - David Sanders
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, MK44 1LQ. Bedfordshire, UK
| | - Todd Gouin
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, MK44 1LQ. Bedfordshire, UK
| | - Steven T J Droge
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, 3508, TD, the Netherlands; Department Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94248, 1090 GE Amsterdam, the Netherlands.
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13
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Groothuis FA, Timmer N, Opsahl E, Nicol B, Droge STJ, Blaauboer BJ, Kramer NI. Influence of in Vitro Assay Setup on the Apparent Cytotoxic Potency of Benzalkonium Chlorides. Chem Res Toxicol 2019; 32:1103-1114. [PMID: 31012305 PMCID: PMC6584903 DOI: 10.1021/acs.chemrestox.8b00412] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The nominal concentration
is generally used to express concentration–effect
relationships in in vitro toxicity assays. However, the nominal concentration
does not necessarily represent the exposure concentration responsible
for the observed effect. Surfactants accumulate at interphases and
likely sorb to in vitro system components such as serum protein and
well plate plastic. The extent of sorption and the consequences of
this sorption on in vitro readouts is largely unknown for these chemicals.
The aim of this study was to demonstrate the effect of sorption to
in vitro components on the observed cytotoxic potency of benzalkonium
chlorides (BAC) varying in alkyl chain length (6–18 carbon
atoms, C6–18) in a basal cytotoxicity assay with
the rainbow trout gill cell line (RTgill-W1). Cells were exposed for
48 h in 96-well plates to increasing concentration of BACs in exposure
medium containing 0, 60 μM bovine serum albumin (BSA) or 10%
fetal bovine serum (FBS). Before and after exposure, BAC concentrations
in exposure medium were analytically determined. Based on freely dissolved
concentrations at the end of the exposure, median effect concentrations
(EC50) decreased with increasing alkyl chain length up
to 14 carbons. For BAC with alkyl chains of 12 or more carbons, EC50’s based on measured concentrations after exposure
in supplement-free medium were up to 25-times lower than EC50’s calculated using nominal concentrations. When BSA or FBS
was added to the medium, a decrease in cytotoxic potency of up to
22 times was observed for BAC with alkyl chains of eight or more carbons.
The results of this study emphasize the importance of expressing the
in vitro readouts as a function of a dose metric that is least influenced
by assay setup to compare assay sensitivities and chemical potencies.
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Affiliation(s)
- Floris A Groothuis
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Niels Timmer
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Eystein Opsahl
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Beate Nicol
- Safety & Environmental Assurance Centre , Unilever U.K. , Colworth Science Park, Sharnbrook, Bedford MK44 1LQ , United Kingdom
| | - Steven T J Droge
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Bas J Blaauboer
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
| | - Nynke I Kramer
- Institute for Risk Assessment Sciences , Utrecht University , PO Box 80177, 3508 TD Utrecht , The Netherlands
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14
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Timmer N, Gore D, Sanders D, Gouin T, Droge STJ. Toxicity mitigation and bioaccessibility of the cationic surfactant cetyltrimethylammonium bromide in a sorbent-modified biodegradation study. Chemosphere 2019; 222:461-468. [PMID: 30716549 DOI: 10.1016/j.chemosphere.2019.01.152] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 01/24/2019] [Accepted: 01/25/2019] [Indexed: 06/09/2023]
Abstract
Biodegradation potential of cationic surfactants may be hampered by inhibition of inoculum at concentrations required to accurately measure inorganic carbon. At >0.3 mg/L cetyltrimethylammonium bromide (CTAB) negatively impacted degradation of the reference compound aniline. We used silicon dioxide (SiO2) and illite as inorganic sorbents to mitigate toxicity of CTAB by lowering freely dissolved concentrations. In an OECD Headspace Test we tested whether 16.8 mg/L CTAB was readily biodegradable in presence of two concentrations of SiO2 and illite. SiO2 adsorbed 85% and 98% CTAB, resulting in concentrations of 2.5 and 0.34 mg/L, mineralized to CO2 >60% within 16 and 23 d, respectively. With 89% and 99% sorbed to illite, 60% mineralization was reached within 9 and 23 d, respectively. However, higher sorbent concentrations increased time needed to reach >60% mineralization. Thus, desorption kinetics likely decreased bioaccessibility. It is therefore essential to determine appropriate concentrations of mitigating sorbents to render a Headspace Test based on carbon analysis suitable to determine ready biodegradability of compounds which might inhibit inoculum. This would avoid use of expensive radiolabeled compounds. However, high sorbent concentrations can reduce bioaccessibility and limit degradation kinetics, particularly for relatively toxic substances that require strong mitigation.
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Affiliation(s)
- Niels Timmer
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht 3508 TD, the Netherlands
| | - David Gore
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, UK
| | - David Sanders
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, UK
| | - Todd Gouin
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, UK
| | - Steven T J Droge
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht 3508 TD, the Netherlands; Department Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE Amsterdam, the Netherlands.
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15
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Abstract
This study determined the sorption affinity to artificial phospholipid membranes ( KMW) for series of perfluorinated carboxylates (PFCAs), perfluorinated sulfonates (PFSAs), alkyl sulfates (C xSO4), and 1-alkanesulfonates (C xSO3). A sorbent dilution assay with solid supported lipid membranes (SSLM) showed consistent CF2 unit increments of 0.59, and CH2 unit increments of 0.53, for the log KMW of perfluorinated and hydrogenated anions, respectively. PFSAs sorbed 0.90 log units stronger than analogue PFCAs; C xSO4 sorbed 0.75 log units stronger than analogue C xSO3 anions. The log KMW values for the octyl analogues increase in the order H(CH2)8SO3- (1.74) < H(CH2)8SO4- (2.58) < F(CF2)8CO2- (PFNA, 4.04) < F(CF2)8SO3- (PFOS, 4.88). Intrinsic partition ratios determined on a phospholipid coated HPLC column (IAM-HPLC) closely aligned with SSLM KMW values. COSMO-RS based molecular calculations of KMW aligned with SSLM KMW values for hydrogenated anions with C8-C14 alkyl chains but strongly underestimated CF2 and CH2 unit increments for C4-C8 based anions. Dividing the critical narcotic membrane burden of 100 mmol/kg by the experimental KMW predicts lethal baseline toxicity concentrations (LC50,narc). The LC50,narc coincides with the lowest reported acute LC50 values for several anionic surfactants but were on average about an order of magnitude lower.
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Affiliation(s)
- Steven T J Droge
- Department of Freshwater and Marine Ecology (FAME), Institute for Biodiversity and Ecosystem Dynamics (IBED) , Universiteit van Amsterdam (UvA) , Science Park 904 , 1098XH Amsterdam , Netherlands
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16
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de Baat ML, Bas DA, van Beusekom SAM, Droge STJ, van der Meer F, de Vries M, Verdonschot PFM, Kraak MHS. Nationwide screening of surface water toxicity to algae. Sci Total Environ 2018; 645:780-787. [PMID: 30031336 DOI: 10.1016/j.scitotenv.2018.07.214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/16/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
According to the European Water Framework Directive (WFD), chemical water quality is assessed by monitoring 45 priority substances. However, observed toxic effects can often not be attributed to these priority substances, and therefore there is an urgent need for an effect-based monitoring strategy that employs bioassays to identify environmental risk. Algal photosynthesis is a sensitive process that can be applied to identify the presence of hazardous herbicides in surface water. Therefore, the aim of this study was to employ an algal photosynthesis bioassay to assess surface water toxicity to algae and to identify the compounds causing the observed effects. To this purpose, Raphidocelis subcapitata was exposed to surface water samples and after 4.5 h photosynthetic efficiency was determined using PAM fluorometry. In this rapid high throughput bioassay, algal photosynthesis was affected by surface water from only one of 39 locations. Single compounds toxicity confirmation elucidated that the observed effect could be solely attributed to the herbicide linuron, which occurred at 110 times the EQS concentration and which is not included in the WFD priority substances list. In conclusion, applying the algal photosynthesis bioassay enables more efficient and effective assessment of toxicity to primary producers because it: (i) identifies the presence of herbicides that would be overlooked by routine chemical WFD monitoring, and (ii) avoids redundant chemical analyses by focusing only on (non-)target screening in samples with demonstrated effects.
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Affiliation(s)
- M L de Baat
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands.
| | - D A Bas
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands
| | - S A M van Beusekom
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands.
| | - S T J Droge
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands.
| | - F van der Meer
- Wetterskip Fryslân, Fryslânplein 3, 8914 BZ Leeuwarden, the Netherlands.
| | - M de Vries
- Wetterskip Fryslân, Fryslânplein 3, 8914 BZ Leeuwarden, the Netherlands.
| | - P F M Verdonschot
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Department of Freshwater Ecology, Wageningen Environmental Research, Droevendaalsesteeg 4, 6708 PB Wageningen, the Netherlands.
| | - M H S Kraak
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands.
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17
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Fischer FC, Abele C, Droge STJ, Henneberger L, König M, Schlichting R, Scholz S, Escher BI. Cellular Uptake Kinetics of Neutral and Charged Chemicals in in Vitro Assays Measured by Fluorescence Microscopy. Chem Res Toxicol 2018; 31:646-657. [PMID: 29939727 DOI: 10.1021/acs.chemrestox.8b00019] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cellular uptake kinetics are key for understanding time-dependent chemical exposure in in vitro cell assays. Slow cellular uptake kinetics in relation to the total exposure time can considerably reduce the biologically effective dose. In this study, fluorescence microscopy combined with automated image analysis was applied for time-resolved quantification of cellular uptake of 10 neutral, anionic, cationic, and zwitterionic fluorophores in two reporter gene assays. The chemical fluorescence in the medium remained relatively constant during the 24-h assay duration, emphasizing that the proteins and lipids in the fetal bovine serum (FBS) supplemented to the assay medium represent a large reservoir of reversibly bound chemicals with the potential to compensate for chemical depletion by cell uptake, growth, and sorption to well materials. Hence FBS plays a role in stabilizing the cellular dose in a similar way as polymer-based passive dosing, here we term this process as serum-mediated passive dosing (SMPD). Neutral chemicals accumulated in the cells up to 12 times faster than charged chemicals. Increasing medium FBS concentrations accelerated uptake due to FBS-facilitated transport but led to lower cellular concentrations as a result of increased sorption to medium proteins and lipids. In vitro cell exposure results from the interaction of several extra- and intracellular processes, leading to variable and time-dependent exposure between different chemicals and assay setups. The medium FBS plays a crucial role for the thermodynamic equilibria as well as for the cellular uptake kinetics, hence influencing exposure. However, quantification of cellular exposure by an area under the curve (AUC) analysis illustrated that, for the evaluated bioassay setup, current in vitro exposure models that assume instantaneous equilibrium between medium and cells still reflect a realistic exposure because the AUC was typically reduced less than 20% compared to the cellular dose that would result from instantaneous equilibrium.
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Affiliation(s)
- Fabian C Fischer
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Cedric Abele
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Steven T J Droge
- Institute for Biodiversity and Ecosystem Dynamics , University of Amsterdam , Science Park 904 , 1098 XH Amsterdam , Netherlands
| | - Luise Henneberger
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Maria König
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Rita Schlichting
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Stefan Scholz
- Department of Bioanalytical Ecotoxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Beate I Escher
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research - UFZ , Permoserstraße 15 , 04318 Leipzig , Germany.,Environmental Toxicology, Centre for Applied Geoscience , Eberhard Karls University Tübingen , 72074 Tübingen , Germany
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18
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Timmer N, Scherpenisse P, Hermens JLM, Droge STJ. Evaluating solid phase (micro-) extraction tools to analyze freely ionizable and permanently charged cationic surfactants. Anal Chim Acta 2017; 1002:26-38. [PMID: 29306411 DOI: 10.1016/j.aca.2017.11.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/15/2017] [Accepted: 11/19/2017] [Indexed: 10/18/2022]
Abstract
Working with and analysis of cationic surfactants can be problematic since aqueous concentrations are difficult to control, both when taking environmental aqueous samples as well as performing laboratory work with spiked concentrations. For a selection of 32 amine based cationic surfactants (including C8- to C18-alkylamines, C14-dialkyldimethylammonium, C8-tetraalkylammonium, benzalkonium and pyridinium compounds), the extraction from aqueous samples was studied in detail. Aqueous concentrations were determined using solid phase extraction (SPE; 3 mL/60 mg Oasis WCX-SPE cartridges) with recoveries of ≥80% for 30 compounds, and ≥90% for 16 compounds. Sorption to glassware was evaluated in 120 mL flasks, 40 mL vials and 1.5 mL autosampler vials, using 15 mM NaCl, where the glass binding of simple primary amines and quaternary ammonium compounds increased with alkyl chain length. Sorption to the outside of pipette tips (≤20% of total amount in solution) when sampling aqueous solutions may interfere with accurate measurements. Polyacrylate solid phase microextraction (PA-SPME) fibers with two coating thicknesses (7 and 35 μm) were tested as potential extraction devices. The uptake kinetics, pH-dependence and influence of ionic strength on sorption to PA fibers were studied. Changing medium from 100 mM Na+ to 10 mM Ca2+ decreases Kfw with one order of magnitude. Results indicate that for PA-SPME neutral amines are absorbed rather than adsorbed, although the exact sorption mechanism remains to be elucidated. Further research remains necessary to establish a definitive applicability domain for PA-SPME. However, results indicate that alkyl chain lengths ≥14 carbon atoms and multiple alkyl chains become problematic. A calibration curve should always be measured together with the samples. In conclusion, it seems that for amine based surfactants PA-SPME does not provide the reliability and reproducibility necessary for precise sorption experiments, specifically for alkyl chain lengths beyond 12 carbon atoms.
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Affiliation(s)
- Niels Timmer
- Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508 TD Utrecht, The Netherlands
| | - Peter Scherpenisse
- Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508 TD Utrecht, The Netherlands
| | - Joop L M Hermens
- Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508 TD Utrecht, The Netherlands
| | - Steven T J Droge
- Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508 TD Utrecht, The Netherlands; Institute for Biodiversity and Ecosystem Dynamics, Department Freshwater and Marine Ecology, P.O. Box 94248, 1090 GE Amsterdam, The Netherlands.
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19
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Droge STJ, Hermens JLM, Gutsell S, Rabone J, Hodges G. Predicting the phospholipophilicity of monoprotic positively charged amines. Environ Sci Process Impacts 2017; 19:307-323. [PMID: 28218330 DOI: 10.1039/c6em00615a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The sorption affinity of eighty-six charged amine structures to phospholipid monolayers (log KIAM) was determined using immobilized artificial membrane high-performance liquid chromatography (IAM-HPLC). The amine compounds covered the most prevalent types of polar groups, widely ranged in structural complexity, and included forty-seven pharmaceuticals, as well as several narcotics and pesticides. Amine type specific corrective increments were used to align log KIAM data with bilayer membrane sorption coefficients (KMW(IAM)). Using predicted sorption affinities of neutral amines, we evaluated the difference (scaling factor ΔMW) with the measured log KMW(IAM) for cationic amines. The ΔMW values were highly variable, ranging from -2.37 to +2.3 log units. For each amine type, polar amines showed lower ΔMW values than hydrocarbon based amines (CxHyN+). COSMOmic software was used to directly calculate the partitioning coefficient of ionic structures into a phospholipid bilayer (KDMPC-W,cation), including quaternary ammonium compounds. The resulting root mean square error (RMSE) between log KDMPC-W,cation and log KMW(IAM) was 0.83 for all eighty-six polar amines, and 0.47 for sixty-eight CxHyN+ amines. The polar amines were then split into five groups depending on polarity and structural complexity, and corrective increments for each group were defined to improve COSMOmic predictions. Excluding only the group with sixteen complex amine structures (≥4 polar groups, Mw > 400, including several macrolide antibiotics), the resulting RMSE for corrected KDMPC-W,cation values improved to 0.45 log units for the remaining set of 138 polar and CxHyN+ amines.
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Affiliation(s)
- S T J Droge
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3508 TD Utrecht, The Netherlands
| | - J L M Hermens
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3508 TD Utrecht, The Netherlands
| | - S Gutsell
- Safety and Environmental Assurance Centre, Unilever, Sharnbrook, Bedford, UK
| | - J Rabone
- Safety and Environmental Assurance Centre, Unilever, Sharnbrook, Bedford, UK
| | - G Hodges
- Safety and Environmental Assurance Centre, Unilever, Sharnbrook, Bedford, UK
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20
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Timmer N, Droge STJ. Sorption of Cationic Surfactants to Artificial Cell Membranes: Comparing Phospholipid Bilayers with Monolayer Coatings and Molecular Simulations. Environ Sci Technol 2017; 51:2890-2898. [PMID: 28187261 PMCID: PMC5343551 DOI: 10.1021/acs.est.6b05662] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This study reports the distribution coefficient between phospholipid bilayer membranes and phosphate buffered saline (PBS) medium (DMW,PBS) for 19 cationic surfactants. The method used a sorbent dilution series with solid supported lipid membranes (SSLMs). The existing SSLM protocol, applying a 96 well plate setup, was adapted to use 1.5 mL glass autosampler vials instead, which facilitated sampling and circumvented several confounding loss processes for some of the cationic surfactants. About 1% of the phospholipids were found to be detached from the SSLM beads, resulting in nonlinear sorption isotherms for compounds with log DMW values above 4. Renewal of the medium resulted in linear sorption isotherms. DMW values determined at pH 5.4 demonstrated that cationic surfactant species account for the observed DMW,PBS. Log DMW,PBS values above 5.5 are only experimentally feasible with lower LC-MS/MS detection limits and/or concentrated extracts of the aqueous samples. Based on the number of carbon atoms, dialkylamines showed a considerably lower sorption affinity than linear alkylamine analogues. These SSLM results closely overlapped with measurements on a chromatographic tool based on immobilized artificial membranes (IAM-HPLC) and with quantum-chemistry based calculations with COSMOmic. The SSLM data suggest that IAM-HPLC underestimates the DMW of ionized primary and secondary alkylamines by 0.8 and 0.5 log units, respectively.
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21
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Chen Y, Hermens JLM, Jonker MTO, Arnot JA, Armitage JM, Brown T, Nichols JW, Fay KA, Droge STJ. Which Molecular Features Affect the Intrinsic Hepatic Clearance Rate of Ionizable Organic Chemicals in Fish? Environ Sci Technol 2016; 50:12722-12731. [PMID: 27934284 DOI: 10.1021/acs.est.6b03504] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Greater knowledge of biotransformation rates for ionizable organic compounds (IOCs) in fish is required to properly assess the bioaccumulation potential of many environmentally relevant contaminants. In this study, we measured in vitro hepatic clearance rates for 50 IOCs using a pooled batch of liver S9 fractions isolated from rainbow trout (Oncorhynchus mykiss). The IOCs included four types of strongly ionized acids (carboxylates, phenolates, sulfonates, and sulfates), three types of strongly ionized bases (primary, secondary, tertiary amines), and a pair of quaternary ammonium compounds (QACs). Included in this test set were several surfactants and a series of beta-blockers. For linear alkyl chain IOC analogues, biotransformation enzymes appeared to act directly on the charged terminal group, with the highest clearance rates for tertiary amines and sulfates and no clearance of QACs. Clearance rates for C12-IOCs were higher than those for C8-IOC analogues. Several analogue series with multiple alkyl chains, branched alkyl chains, aromatic rings, and nonaromatic rings were evaluated. The likelihood of multiple reaction pathways made it difficult to relate all differences in clearance to specific molecular features the tested IOCs. Future analysis of primary metabolites in the S9 assay is recommended to further elucidate biotransformation pathways for IOCs in fish.
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Affiliation(s)
- Yi Chen
- Institute for Risk Assessment Sciences, Utrecht University , Utrecht, 3508 TD, The Netherlands
| | - Joop L M Hermens
- Institute for Risk Assessment Sciences, Utrecht University , Utrecht, 3508 TD, The Netherlands
| | - Michiel T O Jonker
- Institute for Risk Assessment Sciences, Utrecht University , Utrecht, 3508 TD, The Netherlands
| | - Jon A Arnot
- Department of Physical and Environmental Sciences, University of Toronto Scarborough , Toronto, Ontario M1C 1A4, Canada
- ARC Arnot Research and Consulting , Toronto, Ontario M4M 1W4, Canada
| | - James M Armitage
- Department of Physical and Environmental Sciences, University of Toronto Scarborough , Toronto, Ontario M1C 1A4, Canada
- ARC Arnot Research and Consulting , Toronto, Ontario M4M 1W4, Canada
| | - Trevor Brown
- ARC Arnot Research and Consulting , Toronto, Ontario M4M 1W4, Canada
| | - John W Nichols
- US Environmental Protection Agency , Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, Duluth, Minnesota 55804, United States
| | - Kellie A Fay
- US Environmental Protection Agency , Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, Duluth, Minnesota 55804, United States
| | - Steven T J Droge
- Institute for Risk Assessment Sciences, Utrecht University , Utrecht, 3508 TD, The Netherlands
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Droge STJ, Hermens JLM, Rabone J, Gutsell S, Hodges G. Phospholipophilicity of CxHyN(+) amines: chromatographic descriptors and molecular simulations for understanding partitioning into membranes. Environ Sci Process Impacts 2016; 18:1011-23. [PMID: 27118065 DOI: 10.1039/c6em00118a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Using immobilized artificial membrane high-performance liquid chromatography (IAM-HPLC) the sorption affinity of 70 charged amine structures to phospholipids was determined. The amines contained only 1 charged moiety and no other polar groups, the rest of the molecule being aliphatic and/or aromatic hydrocarbon groups. We systematically evaluated the influence of the amine type (1°, 2°, 3° amines and quaternary ammonium), alkyl chain branching, phenyl ring positioning, charge positioning (terminal vs. central in the molecule) on the phospholipid-water partitioning coefficient (KPLIPW). These experimental results were compared with quantum-chemistry based three-dimensional (3D) molecular simulations of the partitioning of charged amines, including the most likely solute conformers, using a hydrated phospholipid bilayer in the COSMOmic module of COSMOtherm software. Both IAM-HPLC retention data and the simulations suggest that the molecular orientation of charged amines at the location in the bilayer with the lowest calculated Gibbs free energy exerts a strong influence over the partitioning within the membrane. The most favourable position of charged amines coincides with the region where the phosphate anions in the phospholipid bilayer are most abundant. Hydrocarbon units oriented in this layer are located more towards the aqueous phase and contribute less to the overall membrane affinity than hydrocarbon units extending into the more hydrophobic core of the bilayer. COSMOmic simulations explain most of the trends between the structural differences observed in IAM-HPLC based KPLIPW. For this set of cationic structures, the mean absolute difference between COSMOmic simulations and IAM-HPLC data, accounting only for amine type corrective increments, is 0.31 log units.
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Affiliation(s)
- S T J Droge
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3508 TD Utrecht, The Netherlands.
| | - J L M Hermens
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3508 TD Utrecht, The Netherlands.
| | - J Rabone
- Safety and Environmental Assurance Centre, Unilever, Sharnbrook, Bedford, UK
| | - S Gutsell
- Safety and Environmental Assurance Centre, Unilever, Sharnbrook, Bedford, UK
| | - G Hodges
- Safety and Environmental Assurance Centre, Unilever, Sharnbrook, Bedford, UK
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23
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Affiliation(s)
- Steven T. J. Droge
- Institute for Risk Assessment
Sciences, Utrecht University, Yalelaan 104, 3508 TD Utrecht, The Netherlands
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Chen Y, Geurts M, Sjollema SB, Kramer NI, Hermens JLM, Droge STJ. Acute toxicity of the cationic surfactant C12-benzalkonium in different bioassays: how test design affects bioavailability and effect concentrations. Environ Toxicol Chem 2014; 33:606-15. [PMID: 24273010 DOI: 10.1002/etc.2465] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 09/25/2013] [Accepted: 11/14/2013] [Indexed: 05/19/2023]
Abstract
Using an ion-exchange-based solid-phase microextraction (SPME) method, the freely dissolved concentrations of C12-benzalkonium were measured in different toxicity assays, including 1) immobilization of Daphnia magna in the presence or absence of dissolved humic acid; 2) mortality of Lumbriculus variegatus in the presence or absence of a suspension of Organisation for Economic Co-Operation and Development (OECD) sediment; 3) photosystem II inhibition of green algae Chlorella vulgaris; and 4) viability of in vitro rainbow trout gill cell line (RTgill-W1) in the presence or absence of serum proteins. Furthermore, the loss from chemical adsorption to the different test vessels used in these tests was also determined. The C12-benzalkonium sorption isotherms to the different sorbent phases were established as well. Our results show that the freely dissolved concentration is a better indicator of the actual exposure concentration than the nominal or total concentration in most test assays. Daphnia was the most sensitive species to C12-benzalkonium. The acute Daphnia and Lumbriculus tests both showed no enhanced toxicity from possible ingestion of sorbed C12-benzalkonium in comparison with water-only exposure, which is in accordance with the equilibrium partitioning theory. Moreover, the present study demonstrates that commonly used sorbent phases can strongly affect bioavailability and observed effect concentrations for C12-benzalkonium. Even stronger effects of decreased actual exposure concentrations resulting from sorption to test vessels, cells, and sorbent phases can be expected for more hydrophobic cationic surfactants.
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Affiliation(s)
- Yi Chen
- Institute for Risk Assessment Sciences, Utrecht University, The Netherlands
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25
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Chen Y, Geurts M, Sjollema SB, Kramer NI, Hermens JLM, Droge STJ. Acute toxicity of the cationic surfactant C12-benzalkonium in different bioassays: how test design affects bioavailability and effect concentrations. Environ Toxicol Chem 2014. [PMID: 24273010 DOI: 10.1002/etc.246533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Using an ion-exchange-based solid-phase microextraction (SPME) method, the freely dissolved concentrations of C12-benzalkonium were measured in different toxicity assays, including 1) immobilization of Daphnia magna in the presence or absence of dissolved humic acid; 2) mortality of Lumbriculus variegatus in the presence or absence of a suspension of Organisation for Economic Co-Operation and Development (OECD) sediment; 3) photosystem II inhibition of green algae Chlorella vulgaris; and 4) viability of in vitro rainbow trout gill cell line (RTgill-W1) in the presence or absence of serum proteins. Furthermore, the loss from chemical adsorption to the different test vessels used in these tests was also determined. The C12-benzalkonium sorption isotherms to the different sorbent phases were established as well. Our results show that the freely dissolved concentration is a better indicator of the actual exposure concentration than the nominal or total concentration in most test assays. Daphnia was the most sensitive species to C12-benzalkonium. The acute Daphnia and Lumbriculus tests both showed no enhanced toxicity from possible ingestion of sorbed C12-benzalkonium in comparison with water-only exposure, which is in accordance with the equilibrium partitioning theory. Moreover, the present study demonstrates that commonly used sorbent phases can strongly affect bioavailability and observed effect concentrations for C12-benzalkonium. Even stronger effects of decreased actual exposure concentrations resulting from sorption to test vessels, cells, and sorbent phases can be expected for more hydrophobic cationic surfactants.
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Affiliation(s)
- Yi Chen
- Institute for Risk Assessment Sciences, Utrecht University, The Netherlands
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Droge STJ, Goss KU. Sorption of organic cations to phyllosilicate clay minerals: CEC-normalization, salt dependency, and the role of electrostatic and hydrophobic effects. Environ Sci Technol 2013; 47:14224-32. [PMID: 24266737 DOI: 10.1021/es403187w] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Sorption to the phyllosilicate clay minerals Illite, kaolinite, and bentonite has been studied for a wide variety of organic cations using a flow-through method with fully aqueous medium as the eluent. Linear isotherms were observed at concentrations below 10% of the cation-exchange capacity (CEC) for Illite and kaolinite and below 1 mmol/kg (<1% CEC) for bentonite. Sorption to clays was strongly influenced by the electrolyte composition of the eluent but with a consistent trend for a diverse set of compounds on all clays, thus allowing for empirical correction factors. When sorption affinities for a given compound to a given clay are normalized to the CEC of the clay, the differences in sorption affinities between clays are reduced to less than 0.5 log units for most compounds. Although CEC-normalized sorption of quaternary ammonium compounds to clay was up to 10-fold higher than CEC-normalized sorption to soil organic matter, CEC-normalized sorption for most compounds was comparable between clays and soil organic matter. The clay fraction is thus a potentially relevant sorption phase for organic cations in many soils. The sorption data for organic cations to clay showed several regular trends with molecular structure but also showed quite a few systematic effects that we cannot explain. A model on the basis of the molecular size and charge density at the ionized nitrogen is used here as a tool to obtain benchmark values that elucidate the effect of specific polar moieties on the sorption affinity.
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Affiliation(s)
- Steven T J Droge
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research-UFZ , Permoserstrasse 15, 04318 Leipzig, Germany
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Droge STJ, Goss KU. Development and evaluation of a new sorption model for organic cations in soil: contributions from organic matter and clay minerals. Environ Sci Technol 2013; 47:14233-41. [PMID: 24266749 DOI: 10.1021/es4031886] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
This study evaluates a newly proposed cation-exchange model that defines the sorption of organic cations to soil as a summed contribution of sorption to organic matter (OM) and sorption to phyllosilicate clay minerals. Sorption to OM is normalized to the fraction organic carbon (fOC), and sorption to clay is normalized to the estimated cation-exchange capacity attributed to clay minerals (CECCLAY). Sorption affinity is specified to a fixed medium composition, with correction factors for other electrolyte concentrations. The model applies measured sorption coefficients to one reference OM material and one clay mineral. If measured values are absent, then empirical relationships are available on the basis of molecular volume and amine type in combination with corrective increments for specific polar moieties. The model is tested using new sorption data generated at pH 6 for two Eurosoils, one enriched in clay and the other, OM, using 29 strong bases (pKa > 8). Using experimental data on reference materials for all tested compounds, model predictions for the two soils differed on average by only -0.1 ± 0.4 log units from measured sorption affinities. Within the chemical applicability domain, the model can also be applied successfully to various reported soil sorption data for organic cations. Particularly for clayish soils, the model shows that sorption of organic cations to clay minerals accounts for more than 90% of the overall affinity.
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Affiliation(s)
- Steven T J Droge
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research-UFZ , Permoserstrasse 15, 04318 Leipzig, Germany
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Chen Y, Hermens JLM, Droge STJ. Influence of organic matter type and medium composition on the sorption affinity of C12-benzalkonium cation. Environ Pollut 2013; 179:153-159. [PMID: 23676325 DOI: 10.1016/j.envpol.2013.04.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/05/2013] [Accepted: 04/08/2013] [Indexed: 06/02/2023]
Abstract
We used the 7-μm polyacrylate ion-exchange SPME fibers to investigate C12-benzalkonium sorption to 10 mg/L natural organic matter at concentrations well below the cation-exchange capacity. C12-BAC sorption at constant medium conditions differed within 0.4 log units for two humic acids (Aldrich, Leonardite) and peat (Sphagnum, Pahokee), with similar nonlinear sorption isotherms (KF ∼ 0.8). Sorption to the SPME fibers and Aldrich humic acid (AHA) was reduced at both low pH and high electrolyte concentration, and reduced more strongly by Ca²⁺ compared with Na⁺ at similar concentrations. Sorption isotherms for AHA (5-50-500 mM Na⁺, pH 6) was modeled successfully by the NICA-Donnan approach, resulting in an intrinsic sorption coefficient of 5.35 (Caq = 1 nM). The NICA-Donnan model further explained the stronger specific binding of Ca²⁺ compared to Na⁺ by differences in Boltzmann factors. This study provides relevant information to interpret bioavailability of quaternary ammonium compounds, and possibly for other organic cations.
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Affiliation(s)
- Yi Chen
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands.
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Droge STJ, Goss KU. Ion-exchange affinity of organic cations to natural organic matter: influence of amine type and nonionic interactions at two different pHs. Environ Sci Technol 2013; 47:798-806. [PMID: 23214498 DOI: 10.1021/es3033499] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Sorption to standard soil organic matter (SOM) has been studied for a wide variety of organic cations using a flow through method with fully aqueous medium as eluent. SOM sorption for weak bases (pK(a) 4.5-7) was stronger at pH 4.5 than at pH 7, indicating that the ion-exchange affinity of the cationic species to SOM was higher than the bulk partition coefficient of corresponding neutral species to SOM. In the range of pH 4.5-7, the effect of pH on the sorption coefficients for strong bases with pK(a) > 7 was small, within 0.3 log units. For cations with the molecular formula C(x)H(y)N, sorption was accurately predicted by a model accounting for size (increase with alkyl chain length) and type of charged group (1° amine >4° ammonium of equal size). In addition to the C(x)H(y)N-model, several empirical correction factors were derived from the data for organic cations with polar functional groups. Models based on K(OW) or pK(a) fail to explain differences in sorption affinity of the ionic species. Our data on ion-exchange affinities for 80 organic cations show many examples where specific chemical moieties, for example, CH(2)-units, aromatic rings or hydroxyl groups, contribute differently to the sorption coefficient as compared to bulk partitioning data of neutral compounds. Other sorption models that were evaluated to explain variation between compounds suffered from outliers of more than one log unit and did not reduce relative log mean standard errors below 0.5. A wider range of sorption coefficients and more sorption data in general are required to improve modeling efforts further.
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Affiliation(s)
- Steven T J Droge
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
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Bäuerlein PS, Ter Laak TL, Hofman-Caris RCHM, de Voogt P, Droge STJ. Removal of charged micropollutants from water by ion-exchange polymers -- effects of competing electrolytes. Water Res 2012; 46:5009-5018. [PMID: 22818952 DOI: 10.1016/j.watres.2012.06.048] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 06/21/2012] [Accepted: 06/26/2012] [Indexed: 06/01/2023]
Abstract
A wide variety of environmental compounds of concern, e.g. pharmaceuticals or illicit drugs, are acids or bases that may predominantly be present as charged species in drinking water sources. These charged micropollutants may prove difficult to remove by currently used water treatment steps (e.g. UV/H(2)O(2), activated carbon (AC) or membranes). We studied the sorption affinity of some ionic organic compounds to both AC and different charged polymeric materials. Ion-exchange polymers may be effective as additional extraction phases in water treatment, because sorption of all charged compounds to oppositely charged polymers was stronger than to AC, especially for the double-charged cation metformin. Tested below 1% of the polymer ion-exchange capacity, the sorption affinity of charged micropollutants is nonlinear and depends on the composition of the aqueous medium. Whereas oppositely charged electrolytes do not impact sorption of organic ions, equally charged electrolytes do influence sorption indicating ion-exchange (IE) to be the main sorption mechanism. For the tested polymers, a tenfold increased salt concentration lowered the IE-sorption affinity by a factor two. Different electrolytes affect IE with organic ions in a similar way as inorganic ions on IE-resins, and no clear differences in this trend were observed between the sulphonated and the carboxylated cation-exchanger. Sorption of organic cations is five fold less in Ca(2+) solutions compared to similar concentrations of Na(+), while that of anionic compounds is three fold weaker in SO(4)(2-) solutions compared to equal concentrations of Cl(-).
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Affiliation(s)
- Patrick S Bäuerlein
- KWR Watercycle Research Institute, Groningenhaven 7, P.O. Box 1072, 3430 BB Nieuwegein, The Netherlands.
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Schenzel J, Goss KU, Schwarzenbach RP, Bucheli TD, Droge STJ. Experimentally determined soil organic matter-water sorption coefficients for different classes of natural toxins and comparison with estimated numbers. Environ Sci Technol 2012; 46:6118-6126. [PMID: 22540838 DOI: 10.1021/es300361g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Although natural toxins, such as mycotoxins or phytoestrogens are widely studied and were recently identified as micropollutants in the environment, many of their environmentally relevant physicochemical properties have not yet been determined. Here, the sorption affinity to Pahokee peat, a model sorbent for soil organic matter, was investigated for 29 mycotoxins and two phytoestrogens. Sorption coefficients (K(oc)) were determined with a dynamic HPLC-based column method using a fully aqueous mobile phase with 5 mM CaCl(2) at pH 4.5. Sorption coefficients varied from less than 10(0.7) L/kg(oc) (e.g., all type B trichothecenes) to 10(4.0) L/kg(oc) (positively charged ergot alkaloids). For the neutral compounds the experimental sorption data set was compared with predicted sorption coefficients using various models, based on molecular fragment approaches (EPISuite's KOCWIN or SPARC), poly parameter linear free energy relationship (pp-LFER) in combination with predicted descriptors, and quantum-chemical based software (COSMOtherm)). None of the available models was able to adequately predict absolute K(oc) numbers and relative differences in sorption affinity for the whole set of neutral toxins, largely because mycotoxins exhibit highly complex structures. Hence, at present, for such compounds fast and consistent experimental techniques for determining sorption coefficients, as the one used in this study, are required.
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Affiliation(s)
- Judith Schenzel
- Agroscope Reckenholz-Taenikon, Research Station ART, CH-8046 Zurich, Switzerland
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Endo S, Droge STJ, Goss KU. Polyparameter Linear Free Energy Models for Polyacrylate Fiber−Water Partition Coefficients to Evaluate the Efficiency of Solid-Phase Microextraction. Anal Chem 2011; 83:1394-400. [DOI: 10.1021/ac102868e] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Satoshi Endo
- Department of Analytical Environmental Chemistry, UFZ − Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Steven T. J. Droge
- Department of Analytical Environmental Chemistry, UFZ − Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands
| | - Kai-Uwe Goss
- Department of Analytical Environmental Chemistry, UFZ − Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
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Droge STJ, Hermens JLM. Alcohol ethoxylate mixtures in marine sediment: competition for adsorption sites affects the sorption behaviour of individual homologues. Environ Pollut 2010; 158:3116-3122. [PMID: 20667636 DOI: 10.1016/j.envpol.2010.06.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 06/17/2010] [Accepted: 06/29/2010] [Indexed: 05/29/2023]
Abstract
Mineral surfaces form the main sorption phase for alcohol ethoxylates (AEs) in marine sediment. Competition for adsorption sites is investigated for marine sediment and kaolinite clay using simple mixtures of AE homologues. For both sorbents, adsorption sites on mineral surfaces can be effectively blocked by an AE homologue with the strongest adsorption affinity. The strongly adsorbed AE, however, forms a second sorption phase to which weakly adsorbing AE will sorb, forming bilayers. An extended dual-mode model accounts for competition effects, while still based on sorption properties of individual compounds. Competition effects become apparent when total adsorbed concentrations reach approximately 10% of the adsorption capacity. Deviations from individual sorption isotherms depend on affinity constants and dissolved homologue composition. Competition will not often occur in contaminated field sediments, with AEs concentrations usually far below the adsorption capacity, but will affect sorption studies, sediment toxicity tests or applications with nonionic surfactant mixtures.
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Affiliation(s)
- Steven T J Droge
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Yalelaan 2, 3584 CL Utrecht, The Netherlands.
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Arp HPH, Droge STJ, Endo S, Giger W, Goss KU, Hawthorne SB, Mabury SA, Mayer P, McLachlan MS, Pankow JF, Schwarzenbach RP, Wania F, Xing B. More of EPA's SPARC online calculator--the need for high-quality predictions of chemical properties. Environ Sci Technol 2010; 44:4400-4401. [PMID: 20476780 DOI: 10.1021/es100437g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Rico-Rico A, Droge STJ, Hermens JLM. Predicting sediment sorption coefficients for linear alkylbenzenesulfonate congeners from polyacrylate-water partition coefficients at different salinities. Environ Sci Technol 2010; 44:941-947. [PMID: 20058863 DOI: 10.1021/es902453s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The effect of the molecular structure and the salinity on the sorption of the anionic surfactant linear alkylbenzenesulfonate (LAS) to marine sediment has been studied. The analysis of several individual LAS congeners in seawater and of one specific LAS congener at different dilutions of seawater was carried out after extraction by polyacrylate solid-phase microextraction (SPME) fibers. Sorption isotherms for the tested LAS congeners on marine sediment and at different ionic composition were all nonlinear with a constant Freundlich exponent (n(F)) of 0.78 +/- 0.05. Differences in LAS sorption of a number of congeners were similar to the differences among the linear partition coefficients (K(fw)) observed for the polyacrylate SPME fibers in seawater. The sorption of LAS to both the sediment and the SPME fiber significantly decreased in media with lower salinity. Dissolved calcium could fully account for the changed affinity of LAS for the SPME fiber, although the high sorption in seawater was also equaled by a corresponding dissolved concentration of NaCl only. Sediment sorption coefficients of a single LAS congener at varying ionic composition was not as strongly related to the K(fw) values as the relation observed for different LAS compounds in seawater, likely because sorption mechanisms are different in both phases. In the absence of experimental data for octanol-water coefficients (K(ow)) of (i) individual LAS congeners at (ii) different ionic compositions, the use of K(fw) as a tool to predict sorption and other hydrophobicity-related processes is suggested.
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Affiliation(s)
- Angeles Rico-Rico
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
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Droge STJ, Yarza-Irusta L, Hermens JLM. Modeling nonlinear sorption of alcohol ethoxylates to sediment: the influence of molecular structure and sediment properties. Environ Sci Technol 2009; 43:5712-5718. [PMID: 19731667 DOI: 10.1021/es900452p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The nonlinear sorption of individual alcohol ethoxylate (AE) homologues was studied as a function of the chemical structure of AE and properties of six marine sediments and three clay minerals. All sorption data for both sediments and clays are well described by a dual-mode model, combining a Langmuir and linear sorption term. The nonlinear isotherms of a single homologue on different substrates almost overlap when sorbed concentrations are expressed per specific surface area. Below and above the Langmuir maximum capacity, isotherms approach linearity. Accordingly, it is demonstrated for nine individual AE that the two linear sorption coefficients for the clay mineral illite are predictive within a factor of two for a North Sea sediment. The linear sorption term at high concentrations is likely related to bilayer formation on the mineral surfaces, for both clays and sediments. Adsorption and bilayer formation to mineral surfaces dominate the sorption behavior of most AE homologues to the tested marine sediments. The two fitted sorption coefficients correlate well with the polar and nonpolar chain lengths of the AE. The enhanced nonlinearity of isotherms for AE with longer ethoxylate chains is explained by both an increasing adsorption coefficient and a decreasing bilayer formation affinity with additional ethoxylate units.
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Affiliation(s)
- Steven T J Droge
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
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Droge STJ, Postma JF, Hermens JLM. Sediment toxicity of a rapidly biodegrading nonionic surfactant: Comparing the equilibrium partitioning approach with measurements in pore water. Environ Sci Technol 2008; 42:4215-4221. [PMID: 18589990 DOI: 10.1021/es702802p] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The equilibrium partitioning theory (EqP) assumes that the toxicity of nonionic surfactants in sediment can be predicted from water-only toxicity data as long as the effect concentrations are properly normalized for chemical activity. Therefore, in marine sediment toxicity tests with the model alcohol ethoxylate (AE), C12EO8, freely dissolved concentrations were both measured via solid-phase microextraction and predicted using sorption coefficients. In fully equilibrated test systems (including the overlying water), both methods showed that concentrations in the pore water of the spiked sediment layer causing 50% mortality (LC50) to the amphipod Corophium volutator were in the same range as LC50 values for amphipods exposed to AE in seawater only. In the sediment systems, AE concentrations in the pore water remained constant up to 15 days, while concentrations in the water overlying the sediment decreased to less than 1% of initial concentrations within 6 days due to biodegradation. In such disequilibrated test systems, C. volutator survived pore water dissolved concentrations that were above the LC50. Apparently, this burrowing amphipod is able to exploit the low chemical activity in the overlying water as a refuge from sediment exposure.
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Affiliation(s)
- Steven T J Droge
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80178, 3508 TD Utrecht, The Netherlands.
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Droge STJ, Hermens JLM. Nonlinear sorption of three alcohol ethoxylates to marine sediment: a combined Langmuir and linear sorption process? Environ Sci Technol 2007; 41:3192-8. [PMID: 17539525 DOI: 10.1021/es062608z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Alcohol ethoxylates (AE) are nonionic surfactants mainly used in laundry cleaning products. The relation between particle bound and freely dissolved concentrations is an important entity in risk assessment. The mechanistic understanding of AE sorption is still poor, hampering extrapolations from laboratory studies to the field. We studied the sorption of three AE with 8 EO units but with increasing alkyl chains (C10, C12, and C14) to a marine sediment. Solid-phase microextraction, using polyacrylate as the extraction phase, was applied to measure freely dissolved concentrations in pore water. A model that combines a Langmuir and a linear sorption term fitted the nonlinear sorption data to sediment well. At low aqueous concentrations, adsorption dominates over absorption leading to higher distribution coefficients for AE at low field concentrations. This dual-mode model offers the possibility to extrapolate to other AE homologues and other marine sediments and also from high to low field concentrations.
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Affiliation(s)
- Steven T J Droge
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3584 CL Utrecht, The Netherlands.
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Droge STJ, Sinnige TL, Hermens JLM. Analysis of Freely Dissolved Alcohol Ethoxylate Homologues in Various Seawater Matrixes Using Solid-Phase Microextraction. Anal Chem 2007; 79:2885-91. [PMID: 17338502 DOI: 10.1021/ac0620260] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Solid-phase microextraction fibers (SPME) were tested as tools to determine freely dissolved alcohol ethoxylate (AE) surfactants in seawater matrixes. Partitioning of a wide range of AE homologues into a 35-mum polyacrylate fiber coating was linearly related to aqueous concentrations as low as submicrograms per liter, with high reproducibility. The exposure time needed to reach equilibrium between aqueous phase and the SPME fiber depended on the fiber-water partitioning coefficient (Kfw) of the AE homologue. Specific attention was given to the influence of various matrixes on the analysis via SPME. The presence of sediment increases the uptake kinetics of AE homologues for which diffusion in the aqueous phase is rate limiting. The Kfw in equilibrated systems was not affected by the presence of other homologues, micelles, or varying amounts of sediment phase. SPME is therefore a suitable tool for analysis of AE in sorption studies and sediment toxicity tests. A strong linear relation was observed between Kfw and the hydrophobicity of the AE homologue, using estimated octanol-water partition coefficients. This relation can be used to predict the partitioning coefficient of any AE homologue to the SPME fiber, which facilitates the analysis of complex mixtures.
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Affiliation(s)
- Steven T J Droge
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3584 CL Utrecht, the Netherlands.
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Droge STJ, Paumen ML, Bleeker EAJ, Kraak MHS, Van Gestel CAM. Chronic toxicity of polycyclic aromatic compounds to the springtail Folsomia candida and the enchytraeid Enchytraeus crypticus. Environ Toxicol Chem 2006; 25:2423-31. [PMID: 16986798 DOI: 10.1897/05-628r.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
An urgent need exists for incorporating heterocyclic compounds and (bio)transformation products in ecotoxicological test schemes and risk assessment of polycyclic aromatic compounds (PACs). The aim of the present study therefore was to determine the chronic effects of (heterocyclic) PACs on two terrestrial invertebrates, the springtail Folsomia candida and the enchytraeid Enchytraeus crypticus. The effects of 11 PACs were determined in chronic experiments using reproduction and survival as endpoints. The results demonstrated that as far as narcosis-induced mortality is concerned, effects of both homocyclic and heterocyclic PACs are well described by the relationship between estimated pore-water 50% lethal concentrations and log Kow. In contrast, specific effects on reproduction varied between species and between compounds as closely related as isomers, showing up as deviations from the relationship between pore-water 50% effect concentrations and log Kow. These unpredictable specific effects on reproduction force one to test the toxicity of these PACs to populations of soil invertebrates to obtain reliable effect concentrations for use in risk assessment of PACs.
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Affiliation(s)
- Steven T J Droge
- Department of Animal Ecology, Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
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