1
|
Poole CF. The effect of the assigned descriptors for phthalate esters on the characterization of their separation properties using the solvation parameter model. J Chromatogr A 2023; 1707:464296. [PMID: 37595351 DOI: 10.1016/j.chroma.2023.464296] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/20/2023]
Abstract
Revised descriptors are determined for fifteen phthalate esters for use in the solvation parameter model and form part of the Wayne State University (WSU) compound descriptor database. For thirteen phthalate esters a comparison is made with the same compounds in the Abraham descriptor database. Gas chromatographic retention factors on poly(methyloctylsiloxane), SPB-Octyl, and poly(cyanopropylphenyldimethylsiloxane), DB-225, stationary phases are used to facilitate an assessment of the contribution of cavity formation and dispersion interactions, L descriptor, and dipole-type interactions, S descriptor, to the experimental retention factors (log k) for the phthalate esters with minimum interference from competing intermolecular interactions. The results indicate a systematic overprediction of the cavity and dispersion interaction term and underprediction of dipole-type interactions for the Abraham descriptors compared with the WSU descriptors for the phthalate esters. The average absolute deviation (AAD) for 13 phthalate esters on SPB-Octyl is 0.039 (WSU descriptors) compared with 0.252 (Abraham descriptors) and for 9 phthalate esters on DB-225 0.030 (WSU descriptors) compared with 0.167 (Abraham descriptors). The results for dipole-type interactions are confirmed and extended to include the hydrogen-bond basicity of the phthalate esters, B descriptor, by evaluation of partition constants in aqueous biphasic systems and the n-heptane-2,2,2-trifluoroethanol biphasic system. Differences in the contribution of the hydrogen-bond basicity of the phthalate esters to the experimental partition constants are largely random with respect to database selection but important for the accurate prediction of the partition constants. The AAD for the partition constant for 15 phthalate esters is 0.063 (WSU descriptors) compared with 0.320 (Abraham descriptors) for the heptane-2,2,2-trifluoroethanol biphasic system and 0.13 (WSU descriptors) compared with 0.25 (Abraham descriptors) for 9 phthalate esters in the octanol-water biphasic system. The WSU descriptors for the phthalate esters exhibit a better fit with the experimental data for separation systems and are free of the extreme values predicted for the Abraham descriptors for several phthalate esters.
Collapse
Affiliation(s)
- Colin F Poole
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA.
| |
Collapse
|
2
|
Poole CF. The influence of descriptor database selection on the solvation parameter model for separation processes. J Chromatogr A 2023; 1692:463851. [PMID: 36773399 DOI: 10.1016/j.chroma.2023.463851] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023]
Abstract
The distribution of neutral compounds in biphasic separation systems can be described by the solvation parameter model using six solute properties, or descriptors. These descriptors characterize the size (McGowan's characteristic volume), V, excess molar refraction, E, dipolarity/polarizability, S, hydrogen-bond acidity and basicity, A and B, and the gas-liquid partition constant on n-hexadecane at 298.15 K, L. McGowan's characteristic volume and the excess molar refraction for liquids are available by calculation (E requires and experimental refractive index). The other descriptors and excess molar refraction for solids are experimental quantities and subject to greater variation or are estimated using computational or empirical models. Solute descriptors for several thousand compounds are available in the Abraham descriptor database and for several hundred compounds in the WSU descriptor database. These publicly accessible databases were developed independently using different approaches and for many compounds provide different descriptor values. In this report we evaluate the effect of mixing descriptors from the two databases on modeling chromatographic retention factors and liquid-liquid partition constants. It is shown that the two descriptor databases are not interchangeable. The WSU descriptor database consistently demonstrates improved model quality as determined by statistical parameters. Model system constants exhibit a general dependence on database selection with an approximately linear trend as a function of the fraction of compounds assigned descriptors from either database. There is no general model performance advantage to using mixed descriptor datasets and no real cause for concern for relatively large datasets containing < 15 % of compounds with descriptors assigned from the other database. For small datasets, descriptor quality is an important variable for adequate model performance.
Collapse
Affiliation(s)
- Colin F Poole
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA.
| |
Collapse
|
3
|
Recent advances for estimating environmental properties for small molecules from chromatographic measurements and the solvation parameter model. J Chromatogr A 2023; 1687:463682. [PMID: 36502643 DOI: 10.1016/j.chroma.2022.463682] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/24/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022]
Abstract
The transfer of neutral compounds between immiscible phases in chromatographic or environmental systems can be described by six solute properties (solute descriptors) using the solvation parameter model. The solute descriptors are size (McGowan's characteristic volume), V, excess molar refraction, E, dipolarity/polarizability, S, hydrogen-bond acidity and basicity, A and B, and the gas-liquid partition constant on n-hexadecane at 298.15 K, L. V and E for liquids are accessible by calculation but the other descriptors and E for solids are determined experimentally by chromatographic, liquid-liquid partition, and solubility measurements. These solute descriptors are available for several thousand compounds in the Abraham solute descriptor databases and for several hundred compounds in the WSU experimental solute descriptor database. In the first part of this review, we highlight features important in defining each descriptor, their experimental determination, compare descriptor quality for the two organized descriptor databases, and methods for estimating Abraham solute descriptors. In the second part we focus on recent applications of the solvation parameter model to characterize environmental systems and its use for the identification of surrogate chromatographic models for estimating environmental properties.
Collapse
|
4
|
Li Z, Wu D, Guo Y, Mao W, Zhao N, Zhao M, Jin H. Phthalate metabolites in paired human serum and whole blood. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153792. [PMID: 35150672 DOI: 10.1016/j.scitotenv.2022.153792] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/06/2022] [Accepted: 02/06/2022] [Indexed: 06/14/2023]
Abstract
Presence of phthalate metabolites (PMs) in human serum has been well documented. However, the distribution pattern of PMs in different human blood matrixes remains not well known. To investigate this, paired serum and whole blood samples were collected from 145 adults (76 males and 69 females) in Quzhou, China, and analyzed for nine PMs in this study. All PMs had high detection frequencies (> 70%) in human serum and whole blood, except mono benzyl phthalate. Total concentrations of detected PMs in serum and whole blood were 0.70-61 ng/mL (mean 12 ng/mL) and 1.6-33 ng/mL (7.5 ng/mL), respectively. Mono methyl phthalate (MMP), mono (2-ethylhexyl) phthalate, and mono butyl phthalate were consistently the predominant PMs in human serum and whole blood, with the mean concentrations of 3.4 and 2.0 ng/mL, 3.3 and 2.1 ng/mL, and 2.8 and 1.8 ng/mL, respectively. Females had higher mean serum concentrations of PMs, except MBP, than males. Youngest age group (20-30 years) consistently had the lowest mean whole blood levels of all PMs. For the first time, the distribution pattern of PMs in human blood was evaluated based on the calculated partitioning coefficient (Kp) between serum and whole blood. MMP had the highest mean Kp value (1.6; 10th-90th percentile: 1.0-2.2), while mono (2-ethyl-5-oxohexyl) phthalate had the lowest mean Kp value (0.63; 10th-90th percentile: 0.25-1.3). These results help better understand the occurrence of PMs in human blood.
Collapse
Affiliation(s)
- Zhenming Li
- College of Chemical and Engineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Dexin Wu
- Hangzhou Xinjing Environmental Technology Co., Ltd., Hangzhou 310007, PR China
| | - Yu Guo
- Focused Photonics (Hangzhou) Inc., 459 Qianmo Road, Hangzhou 311000, PR China
| | - Weili Mao
- Department of Pharmacy, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou 324000, PR China
| | - Nan Zhao
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Meirong Zhao
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Hangbiao Jin
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China.
| |
Collapse
|
5
|
Salthammer T, Morrison GC. Temperature and indoor environments. INDOOR AIR 2022; 32:e13022. [PMID: 35622714 DOI: 10.1111/ina.13022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/20/2022] [Accepted: 03/13/2022] [Indexed: 06/15/2023]
Abstract
From the thermodynamic perspective, the term temperature is clearly defined for ideal physical systems: A unique temperature can be assigned to each black body via its radiation spectrum, and the temperature of an ideal gas is given by the velocity distribution of the molecules. While the indoor environment is not an ideal system, fundamental physical and chemical processes, such as diffusion, partitioning equilibria, and chemical reactions, are predictably temperature-dependent. For example, the logarithm of reaction rate and equilibria constants are proportional to the reciprocal of the absolute temperature. It is therefore possible to have non-linear, very steep changes in chemical phenomena over a relatively small temperature range. On the contrary, transport processes are more influenced by spatial temperature, momentum, and pressure gradients as well as by the density, porosity, and composition of indoor materials. Consequently, emergent phenomena, such as emission rates or dynamic air concentrations, can be the result of complex temperature-dependent relationships that require a more empirical approach. Indoor environmental conditions are further influenced by the thermal comfort needs of occupants. Not only do occupants have to create thermal conditions that serve to maintain their core body temperature, which is usually accomplished by wearing appropriate clothing, but also the surroundings must be adapted so that they feel comfortable. This includes the interaction of the living space with the ambient environment, which can vary greatly by region and season. Design of houses, apartments, commercial buildings, and schools is generally utility and comfort driven, requiring an appropriate energy balance, sometimes considering ventilation but rarely including the impact of temperature on indoor contaminant levels. In our article, we start with a review of fundamental thermodynamic variables and discuss their influence on typical indoor processes. Then, we describe the heat balance of people in their thermal environment. An extensive literature study is devoted to the thermal conditions in buildings, the temperature-dependent release of indoor pollutants from materials and their distribution in the various interior compartments as well as aspects of indoor chemistry. Finally, we assess the need to consider temperature holistically with regard to the changes to be expected as a result of global emergencies such as climate change.
Collapse
Affiliation(s)
- Tunga Salthammer
- Department of Material Analysis and Indoor Chemistry, Fraunhofer WKI, Braunschweig, Germany
| | - Glenn C Morrison
- Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
6
|
Chung Y, Vermeire FH, Wu H, Walker PJ, Abraham MH, Green WH. Group Contribution and Machine Learning Approaches to Predict Abraham Solute Parameters, Solvation Free Energy, and Solvation Enthalpy. J Chem Inf Model 2022; 62:433-446. [PMID: 35044781 DOI: 10.1021/acs.jcim.1c01103] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We present a group contribution method (SoluteGC) and a machine learning model (SoluteML) to predict the Abraham solute parameters, as well as a machine learning model (DirectML) to predict solvation free energy and enthalpy at 298 K. The proposed group contribution method uses atom-centered functional groups with corrections for ring and polycyclic strain while the machine learning models adopt a directed message passing neural network. The solute parameters predicted from SoluteGC and SoluteML are used to calculate solvation energy and enthalpy via linear free energy relationships. Extensive data sets containing 8366 solute parameters, 20,253 solvation free energies, and 6322 solvation enthalpies are compiled in this work to train the models. The three models are each evaluated on the same test sets using both random and substructure-based solute splits for solvation energy and enthalpy predictions. The results show that the DirectML model is superior to the SoluteML and SoluteGC models for both predictions and can provide accuracy comparable to that of advanced quantum chemistry methods. Yet, even though the DirectML model performs better in general, all three models are useful for various purposes. Uncertain predicted values can be identified by comparing the three models, and when the 3 models are combined together, they can provide even more accurate predictions than any one of them individually. Finally, we present our compiled solute parameter, solvation energy, and solvation enthalpy databases (SoluteDB, dGsolvDBx, dHsolvDB) and provide public access to our final prediction models through a simple web-based tool, software packages, and source code.
Collapse
Affiliation(s)
- Yunsie Chung
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Florence H Vermeire
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Haoyang Wu
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Pierre J Walker
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.,Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Michael H Abraham
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, United Kingdom
| | - William H Green
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
7
|
Salthammer T, Grimme S, Stahn M, Hohm U, Palm WU. Quantum Chemical Calculation and Evaluation of Partition Coefficients for Classical and Emerging Environmentally Relevant Organic Compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:379-391. [PMID: 34931808 DOI: 10.1021/acs.est.1c06935] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Octanol/water (KOW), octanol/air (KOA), and hexadecane/air (KHdA) partition coefficients are calculated for 67 organic compounds of environmental concern using computational chemistry. The extended CRENSO workflow applied here includes the calculation of extensive conformer ensembles with semiempirical methods and refinement through density functional theory, taking into account solvation models, especially COSMO-RS, and thermostatistical contributions. This approach is particularly advantageous for describing large and nonrigid molecules. With regard to KOW and KHdA, one can refer to many experimental data from direct and indirect measurement methods, and very good matches with results from our quantum chemical workflow are evident. In the case of the KOA values, however, good matches are only obtained for the experimentally determined values. Larger systematic deviations between data computed here and available, nonexperimental quantitative structure-activity relationship literature data occur in particular for phthalic acid esters and organophosphate esters. From a critical analysis of the coefficients calculated in this work and comparison with available literature data, we conclude that the presented quantum chemical composite approach is the most powerful so far for calculating reliable partition coefficients because all physical contributions to the conformational free energy are considered and the structure ensembles for the two phases are generated independently and consistently.
Collapse
Affiliation(s)
- Tunga Salthammer
- Department of Material Analysis and Indoor Chemistry, Fraunhofer WKI, 38108 Braunschweig, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, 53115 Bonn, Germany
| | - Marcel Stahn
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, 53115 Bonn, Germany
| | - Uwe Hohm
- Institute of Physical and Theoretical Chemistry, University of Braunschweig─Institute of Technology, 38106 Braunschweig, Germany
| | - Wolf-Ulrich Palm
- Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg, 21335 Lüneburg, Germany
| |
Collapse
|
8
|
Poole CF. Wayne State University experimental descriptor database for use with the solvation parameter model. J Chromatogr A 2020; 1617:460841. [DOI: 10.1016/j.chroma.2019.460841] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/26/2019] [Accepted: 12/31/2019] [Indexed: 01/04/2023]
|
9
|
Domínguez-Romero E, Scheringer M. A review of phthalate pharmacokinetics in human and rat: what factors drive phthalate distribution and partitioning? Drug Metab Rev 2019; 51:314-329. [DOI: 10.1080/03602532.2019.1620762] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Elena Domínguez-Romero
- Research Centre for Toxic Compounds in the Environment (RECETOX), Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Martin Scheringer
- Research Centre for Toxic Compounds in the Environment (RECETOX), Faculty of Science, Masaryk University, Brno, Czech Republic
| |
Collapse
|
10
|
Salthammer T, Goss KU. Predicting the Gas/Particle Distribution of SVOCs in the Indoor Environment Using Poly Parameter Linear Free Energy Relationships. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2491-2499. [PMID: 30688443 DOI: 10.1021/acs.est.8b06585] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Understanding the partitioning of semi volatile organic compounds (SVOCs) between gas phase and particle phase is essential for exposure analysis and risk assessment in the indoor environment. Numerous attempts have been made to calculate gas/particle partitioning coefficients Kip. Single-parameter adsorption and absorption models, which relate Kip to the vapor pressure Ps or the octanol/air distribution coefficient KOA are usually applied. In this work we use poly parameter Linear Free Energy Relationships (pp-LFER) to describe the partitioning behavior of 14 SVOCs with high relevance for the indoor environment. The pp-LFER concept is based on Abraham descriptors and considers interactions between molecule and particle by separate parameters. van der Waals interactions can be approximated by the logarithm of the hexadecane/air partitioning coefficient (log KHdA = L), which is a key parameter for the 14 polar but nonionizable organic esters being studied here. For many of the examined compounds experimentally determined L-values were not available and had to be measured using gas chromatography. It is shown that the pp-LFER method is a strong alternative to single-parameter approaches and gives reliable coefficients for gas/particle distribution in the indoor environment.
Collapse
Affiliation(s)
- Tunga Salthammer
- Fraunhofer WKI , Department of Material Analysis and Indoor Chemistry , Bienroder Weg 54E , 38108 Braunschweig , Germany
| | - Kai-Uwe Goss
- Department Analytical Environmental Chemistry , Helmholtz-Centre for Environmental Research - UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| |
Collapse
|
11
|
Determination of Abraham Model Correlations for Solute Transfer into Propyl Acetate Based on Experimental Activity Coefficient and Solubility Data. J SOLUTION CHEM 2018. [DOI: 10.1007/s10953-018-0743-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
12
|
Chepchirchir BS, Paschke A, Schüürmann G. Passive sampling for spatial and temporal monitoring of organic pollutants in surface water of a rural-urban river in Kenya. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 601-602:453-460. [PMID: 28575823 DOI: 10.1016/j.scitotenv.2017.05.143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 05/11/2017] [Accepted: 05/16/2017] [Indexed: 06/07/2023]
Abstract
Passive sampling is an emerging monitoring strategy for surface waters and can be applied in a range of environments including remote locations. Silicone rubber (SR) as a robust single-phase passive sampler was applied to characterize the spatial and temporal variability of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs) and three phthalates, namely, dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and bis(2-ethylhexyl)phthalate (DEHP) in a tropical river traversing rural and urban catchments. OCPs and PCBs were not detected. Up to 31.8ng/L of freely dissolved concentrations of PAHs were quantified and were dominated by the lower molecular weight members. Mean concentrations of DBP, BBP and DEHP were 72.6ng/L, 3.9ng/L and 7.1ng/L respectively. However, in sampling for phthalates using SR, quality control and assurance remains the key challenge and must always be ensured. Spatial variability in concentrations was evident and could be related to land use. Temporal variability was not significant.
Collapse
Affiliation(s)
- Bilha Saina Chepchirchir
- UFZ - Department of Ecological Chemistry, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany; Institute for Organic Chemistry, Technical University Bergakademie Freiberg, Leipziger Str. 29, 09596 Freiberg, Germany
| | - Albrecht Paschke
- UFZ - Department of Ecological Chemistry, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany.
| | - Gerrit Schüürmann
- UFZ - Department of Ecological Chemistry, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany; Institute for Organic Chemistry, Technical University Bergakademie Freiberg, Leipziger Str. 29, 09596 Freiberg, Germany
| |
Collapse
|
13
|
Lin J, Chen W, Zhu H, Wang C. Determination of free and total phthalates in commercial whole milk products in different packaging materials by gas chromatography-mass spectrometry. J Dairy Sci 2015; 98:8278-84. [PMID: 26454292 DOI: 10.3168/jds.2015-10066] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 08/26/2015] [Indexed: 12/21/2022]
Abstract
We developed a method for extraction and determination of free and total phthalate esters in commercial whole milk products. The free phthalates in milk samples were extracted with ethyl acetate after general pretreatment procedures including protein precipitation, centrifugation, and filtration. The bound phthalates in samples were first desorbed with the aid of ultrasound irradiation before extraction of total phthalates. The separation and determination of phthalates in extracts was performed by gas chromatography coupled with mass spectrometric detection. The detection limits were in the range of 0.09 to 0.36ng/g and the average recovery between 79.1 and 110.3%. The developed methods were applied to extract and determine phthalates in commercial whole milk products with different packaging materials, including plastic, glass, and metal. All samples contained several phthalates, including diethyl, diisobutyl, and bis(2-ethylhexyl) phthalates at concentrations between 2.60 and 156.4ng/g. The identified phthalates occurred in both free and bound forms. The amounts of phthalates in milk samples packaged in glass and metal containers were much lower than those in plastic containers. Plastic packaging materials are a possible source of phthalate contamination in commercial whole milk products, and a considerable portion of bleached phthalates from packaging can be adsorbed on proteins and other solid components of milk.
Collapse
Affiliation(s)
- Jialu Lin
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Wanxin Chen
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Hangcui Zhu
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
| | - Chengjun Wang
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China.
| |
Collapse
|
14
|
Hart E, Grover D, Zettl H, Koshevarova V, Zhang S, Dai C, Acree WE, Sedov IA, Stolov MA, Abraham MH. Abraham model correlations for solute transfer into 2-methoxyethanol from water and from the gas phase. J Mol Liq 2015. [DOI: 10.1016/j.molliq.2015.05.064] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
15
|
Abraham MH, Acree WE, Earp CE, Vladimirova A, Whaley WL. Studies on the hydrogen bond acidity, and other descriptors and properties for hydroxyflavones and hydroxyisoflavones. J Mol Liq 2015. [DOI: 10.1016/j.molliq.2015.05.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
16
|
Abraham MH, Abraham RJ, Aliev AE, Tormena CF. Is there an intramolecular hydrogen bond in 2-halophenols? A theoretical and spectroscopic investigation. Phys Chem Chem Phys 2015; 17:25151-9. [DOI: 10.1039/c5cp04061b] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
H-bonding is the most important interaction in life. We present a theoretical and spectroscopic investigation of intramolecular H-bonding in 2-halophenols.
Collapse
Affiliation(s)
| | | | - Abil E. Aliev
- Department of Chemistry
- University College London
- London
- UK
| | | |
Collapse
|