Analysis of priority pesticides and phenols in Portuguese river water by liquid chromatography-mass spectrometry

Determination of seventeen endocrine disruptor compounds and their spatial and seasonal distribution in Ria Formosa Lagoon (Portugal)

In spite of its outstanding ecological and touristic importance the Ria Formosa Lagoon shows signs of anthropogenic pollution. Nonetheless, until the present survey no studies had ever documented the measurement of natural and pharmaceutical estrogens (17β-estradiol, estrone, and 17α-ethynylestradiol), xenoestrogenic industrial pollutants (4-octylphenol, 4-nonylphenol, and their mono and diethoxylates and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, genistein), and sitosterol in this area. The 17 compounds measured herein are known as endocrine disrupters (EDCs) and act over the endocrine system even in few amounts (ng L(-1)-μg L(-1)). Thus to conclude about the influx of EDCs in the lagoon, water samples were taken every 2 months, during 1 year (2010), in low tide at nine sites distributed along the coastline. Water samples (1 L) were preconcentrated in the Oasis HLB cartridges and cleaned in silica cartridges before their analysis by GC-MS. Data showed the ubiquitous presence of potentially hazardous amounts of estrogens (particularly of ethynylestradiol, up to 24.3 ng L(-1)), nonylphenol (up to 547 ng L(-1)), and sitosterol (up to 12,300 ng L(-1)), mainly in summer, suggesting that the increase of the local number of inhabitants (tourists), the rise of the water temperature (up to 26 °C), and the blooming of local flora may interfere with the water quality parameters. This makes the lagoon a potential model to study. Taking into account the data, it was concluded that there are conditions for the occurrence of endocrine disruption in aquatic animals, even in areas included in the natural park of the Formosa. Besides, both the high amounts of un-ionized ammonia (up to 0.3 mg L(-1)) and phosphates (up to 1.6 mg L(-1)) my pose risks for local fauna and humans.

Applicability of the new 60 μm polyethylene glycol solid-phase microextraction fiber assembly for the simultaneous analysis of six pesticides in water

A solid-phase microextraction (SPME) method has been applied for the simultaneous analysis of six pesticides in water, with polar to moderately polar range, by gas chromatography-mass spectrometry (GC-MS). Two types of fiber coatings [60 µm polyethylene glycol (PEG) and 65 µm polydimethylsiloxane/divinylbenzene (PDMS/DVB)] and the effect of salt (addition of 10 and 25% of NaCl) were compared. The extraction efficiency was higher with PEG than with the PDMS/DVB fiber for all pesticides, with the exception of terbuthylazine and phosmet, and with addition of 25% NaCl. The optimized SPME-GC-MS method, adopting the PEG fiber and the addition of 25% NaCl, in addition to other conditions [60 min of direct dipping of the fiber into the water sample (10 mL) under agitation (250 rpm) at ambient temperature; desorption period of 5 min at 240°C] allowed the determination of all studied pesticides and showed good linearity for concentrations ranging from 0.05 to 5 µg/L. Limits of detection varied between 0.003 and 0.145 µg/L, with values below 0.025 µg/L for most of the analytes. Precision ranged from 4.2 to 12%. The proposed method is fast and simple, and was proven to be reliable for the routine analysis of pesticides in water, primarily for environmental monitoring.

2,4,6-Trichlorophenol mediated increases in extracellular peroxidase activity in three species of Lemnaceae

Chlorinated phenols, or chlorophenols, are persistent priority pollutants that are widespread in the environment. Class III peroxidases are well-characterised plant enzymes that can catalyse the oxidative dechlorination of chlorophenols. Expression of these enzymes by plants is commonly associated with plant stress, therefore limiting scope for phytoremediation. In this study, we have quantitatively compared peroxidase activity and phytotoxicity as a function of 2,4,6-trichlorophenol (TCP) concentration in three species of Lemnaceae; Lemna minor, Lemna gibba and Landoltia punctata. Effects of TCP on the growth rates of the three species differed considerably with L. punctata being the most tolerant species. TCP also affected photosynthetic parameters, causing a decrease in open photosystem II reaction centres (qP) and, in L. punctata only, a decrease in non-photochemical quenching (qN). In parallel, TCP exposure resulted in increased peroxidase activity in all three species. Peroxidase activity in L. minor and L. gibba displayed an inverse relationship with biomass accumulation, i.e. the more growth reduction the more peroxidase activity. In contrast, induction of peroxidase activity in L. punctata was bi-phasic, with a TCP-induced activity peak at concentrations that had no major effect on growth, and further induction under phytotoxic concentrations. The mechanism by which L. punctata recognises and responds to low concentrations of an anthropogenic compound, in the absence of wide-ranging stress, remains enigmatic. However, we conclude that this "window" of peroxidase production in the absence of major growth inhibition offers potential for the development of sustainable, peroxidise-mediated phytoremediation systems.

Does grazing pressure modify diuron toxicity in a biofilm community?

Herbicides affect the structure and functional parameters of fluvial biofilm. Diuron is toxic to primary producers and disrupts endocrine activity. Here, we studied the interaction between this toxicant and several biological compartments in a simple food chain composed of herbivores (the snail Physella [Costatella] acuta) and biofilm. We used indoor experimental channels to which Diuron was added at a realistic concentration (2 mug/L). Bacterial survival and chlorophyll-a and photosynthetic activity were analyzed in the biofilm. We monitored biomass, mortality, reproduction, and motility as end points in the freshwater snail P. acuta. Our results showed that bacterial survival and photosynthetic activity were sensitive to Diuron. Snails were not affected by the herbicide at the concentration tested. No significant interactions between the toxicant and grazers were observed on the biofilm. Reproductive traits, however, were slightly affected, indicating a possible endocrine disruption.

Determination of endocrine disrupting chemicals in surface water and industrial wastewater from Beijing, China

An analytical method was developed for determination of some endocrine-disrupting chemicals in water samples from Beijing, China. Fifty two surface water and 50 industrial wastewater samples were analyzed. The residue was detected in 26 industrial wastewater and 19 surface water samples. Atrazine was detected in 8 samples at different levels ranging from 0.12 to 5.16 microg L(-1), and phenolic compounds were detected in 19 samples ranging from 0.8 to 26.1 microg L(-1). The results show that the main pollutants of surface water samples were atrazine and octylphenol. In industrial wastewater samples, bisphenol A and octylphenol were most commonly found.

Seasonal and spatial distribution of several endocrine-disrupting compounds in the Douro River Estuary, Portugal

Recent studies in the Douro River estuary show signs of pollution in the area and of fish endocrine disruption. However, the chemical nature of the local contamination has not been fully investigated nor have studies checking for the simultaneous presence of endocrine-disrupting chemicals (EDCs), either of animal (estrone, E1; estradiol, E2), pharmaceutical (17alpha-ethynylestradiol, EE2), vegetal (daidzein, DAID; genistein, GEN; biochanin A, BIO-A), or industrial (bisphenol A, BPA; 4-octylphenol, 4-OP; 4-nonylphenol, 4-NP) origins. Thus, the main objective of this study was to examine the presence of these EDCs in estuarine water samples collected, in every season of the year, at nine sampling stations along the estuarine gradient. All samples were processed by two-step solid-phase extraction (Oasis HLB followed by silica) prior to high-performance liquid chromatography with diode-array detection (HPLC-DAD) and gas chromatography-mass spectrometry (GC-MS) analyses. The current data showed that E1 and EE2, all phytoestrogens, and BPA were identified and measured in this estuary. In contrast, 4-OP was only detected by GC-MS and E2 and 4-NP were not found. Additionally, E1 (up to 112.9 ng/L) and EE2 (up to 101.9 ng/L) were both measured in biologically hazardous amounts in winter. In the year sampled, the phytoestrogens suggested a possible seasonal pattern of fluctuation. Both DAID (up to 888.4 ng/L) and GEN (183.6 ng/L) were maximal in early summer, whereas BIO-A (up to 191.4 ng/L) reached its highest concentrations in winter. BPA (up to 10.7 microg/L) also attained highest levels in winter. In December 2005, it is hypothesized that E1, EE2, and BPA concentrations were atypically high due to current drought conditions. Almost all assayed EDCs existed in all seasons and, therefore, might have contributed to endocrine disruption of aquatic animals, previously documented by the high rate of ovotestis in fish caught in this estuary.

Trace level determination of beta-blockers in waste waters by highly selective molecularly imprinted polymers extraction followed by liquid chromatography-quadrupole-linear ion trap mass spectrometry

This paper describes the development of an analytical methodology to determine eight beta-blockers in waste waters using molecularly imprinted polymers (MIPs) as extraction and pre-concentration material, followed by liquid chromatography-quadrupole-linear ion trap mass spectrometry (LC-QqLIT MS). The advantages offered by MIPs, in terms of selectivity and specificity, were compared with the most commonly polymeric materials used (the lipophilic-hydrophilic balanced Oasis HLB cartridges). Even though recoveries achieved with both sorbents were similar, ranging from 50 to 110% for sewage treatment plant (STP) effluent and 40-110 for STP influent, respectively, MIPs provided lower method detection limits than Oasis HLB, due to their specificity for target analytes and closely related analogues. Method detection limits (MDL) achieved using MIPs ranged from 0.2 to 6.4 ng/L for STP effluent and from 0.4 to 6.5 ng/L for STP influent. To highlight the advantages of MIPs against conventional polymeric cartridges, a detailed matrix effects study as well as cross reactivity tests were performed. For the latter purpose, the extraction efficiency of some pharmaceuticals and pesticides belonging to different therapeutic classes was assessed. LC-QqLIT MS, used for quantification and confirmation, proved to be a powerful analytical tool, as instrumental detection limits (IDL) achieved ranged from 0.2 to 2.7 pg injected (in multiple reaction monitoring mode (MRM)). In addition the inclusion of high sensitive MS/MS scans for each compound when working in Information Dependent Acquisition mode (IDA) provided extra confirmation for unequivocal identification of target compounds in complex environmental matrices.

Solid-phase extraction combined with dispersive liquid–liquid microextraction-ultra preconcentration of chlorophenols in aqueous samples

The solid-phase extraction (SPE) joined with the dispersive liquid-liquid microextraction (DLLME) has been developed as an ultra preconcentration technique for the determination of chlorophenols in water samples. Chlorophenols (CPs) were employed as model compounds to assess the extraction procedure and were determined by gas chromatography-electron-capture detection (GC-ECD). In solid-phase extraction-dispersive liquid-liquid microextraction (SPE-DLLME), CPs were adsorbed from a large volume of aqueous samples (100 mL) into 100 mg functionalized styrene-divinylbenzene polymer (PPL) sorbent. After the elution of the desired compounds from the sorbent by using acetone, DLLME technique was performed on the obtained solution. Some important extraction parameters, such as sample solution flow rate, breakthrough volume, sample pH, type and volume of the elution solvent as well as the salt addition, were studied and optimized. The new method (SPE-DLLME) provided an ultra enrichment factor (4390-17,870) for 19 CPs. The calibration graphs were linear in the range of 0.001-20 microg L(-1) and the limits of detection (LODs) ranged from 0.0005 to 0.1 microg L(-1). The relative standard deviations (RSDs, for 10.0 microg L(-1) of MCPs, 5.00 microg L(-1) of DCPs, 0.200 microg L(-1) of TCPs, 0.100 microg L(-1) of TeCPs and PCP) with and without the internal standard varied from 1.1 to 6.4% (n=7) and 2.5-9.7% (n=7), respectively. The relative recoveries of the well, tap and river water samples, spiked with different levels of CPs, were 71-110%, 73-115% and 88-121%, respectively.

Determination of chlorophenols in water samples using simultaneous dispersive liquid–liquid microextraction and derivatization followed by gas chromatography-electron-capture detection

Simultaneous dispersive liquid-liquid microextraction (DLLME) and derivatization combined with gas chromatography-electron-capture detection (GC-ECD) was used to determine chlorophenols (CPs) in water sample. In this derivatization/extraction method, 500 microL acetone (disperser solvent) containing 10.0 microL chlorobenzene (extraction solvent) and 50 microL acetic anhydride (derivatization reagent) was rapidly injected by syringe in 5.00 mL aqueous sample containing CPs (analytes) and K(2)CO(3) (0.5%, w/v). Within a few seconds the analytes derivatized and extracted at the same time. After centrifugation, 0.50 microL of sedimented phase containing enriched analytes was determined by GC-ECD. Some effective parameters on derivatization and extraction, such as extraction and disperser solvent type and their volume, amount of derivatization reagent, derivatization and extraction time, salt addition and amount of K(2)CO(3) were studied and optimized. Under the optimum conditions, enrichment factors and recoveries are in the range of 287-906 and 28.7-90.6%, respectively. The calibration graphs are linear in the range of 0.02-400 microg L(-1) and limit of detections (LODs) are in the range of 0.010-2.0 microg L(-1). The relative standard deviations (RSDs, for 200 microg L(-1) of MCPs, 100 microg L(-1) of DCPs, 4.00 microg L(-1) of TCPs, 2.00 microg L(-1) of TeCPs and PCP in water) with and without using internal standard are in the range of 0.6-4.7% (n=7) and 1.7-7.1% (n=7), respectively. The relative recoveries of well, tap and river water samples which have been spiked with different levels of CPs are 91.6-104.7, 80.8-117.9 and 83.3-101.3%, respectively. The obtained results show that simultaneous DLLME and derivatization combined with GC-ECD is a fast simple method for the determination of CPs in water samples.

New materials in sorptive extraction techniques for polar compounds

This paper provides an overview of the new developments in material and format technology that improve the extraction of polar compounds in several extraction techniques. They mainly include solid-phase extraction, but there are also other sorptive extraction techniques, such as stir bar sorptive extraction and solid-phase microextraction that use either fibers or in-tube devices. We focus on new synthesised materials that are both commercially available and "in-house". Most novel materials that enhance the extraction of polar compounds are hydrophilic and have large specific surface area; however, we also cover other leading technologies, such as sol-gel or monolith. We describe the morphological and chemical properties of these new sorbents so that we can better understand them and relate them to their capability of retaining polar compounds. We discuss the extraction efficiency for polar compounds when these polymers are used as sorptive material and compare them to other materials. We also mention some representative examples of applications.

Solid-phase microextraction liquid chromatography/tandem mass spectrometry for the analysis of chlorophenols in environmental samples

Liquid chromatography with atmospheric pressure chemical ionisation mass spectrometry (LC/APCI-MS), using negative ion detection in a triple quadrupole instrument, was used for the determination of chlorophenols (CPs) in environmental samples. In-source collision-induced dissociation (CID) was compared with MS/MS fragmentation. In general, less fragmentation was observed in MS/MS as compared with in-source CID, with the latter providing more intense fragment ions due to chemical ionisation. Under MS/MS conditions [M - H - HCl](-) was the main fragment ion observed for all compounds except for pentachlorophenol, which showed no fragmentation. For multiple reaction monitoring (MRM) acquisition mode, the transition from [M - H](-) to [M - H - HCl](-) was selected, leading to detection limits down to 0.3 ng injected. Direct and headspace-solid-phase microextraction (HS-SPME) were used as preconcentration procedures for the analysis of CPs in wood and in industrially contaminated soils. CPs were quantified by standard addition, which led to good reproducibility (RSD between 4 and 11%) in both SIM and MRM modes, and detection limits down to ng/g. The combination of MS/MS and in-source CID allowed confirmation of the presence of CPs in environmental samples.

Trace determination of priority pesticides in water by means of high-speed on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry using turbulent-flow chromatography columns for enrichment and a short monolithic column for fast liquid chromatographic separation

An integrated on-line SPE-HPLC-MS/MS system has been developed for the rapid analysis of various trace level priority pesticides in surface and drinking water. Eleven pesticides were included in this study, with various phenylureas, triazines and organophosphorous species among them. Use of turbulent-flow chromatography columns (TFC, 50 x 1 mm, 30-50 microm particle size) as extraction cartridges enables fast on-line SPE at high sampling flow-rate (5 ml/min). Polymeric and carbon based TFC columns (Oasis HLB, Cyclone, Hypercarb) allow complete extraction with good recoveries from water volumes up to 50 ml. On-line coupling to HPLC is performed with re-mixing of the organic TFC eluate with water in front of the analytical column to ensure efficient band focussing. For fast HPLC analysis, a short monolithic column is applied in combination with highly selective API-MS/MS detection. Matrix effects on the APCI-MS/MS signal were found to be reduced by the system to an acceptable minimum. Limits of detection, determined for 10-ml samples of river water were in the range between 0.4 and 13 ng/l typically, except trifluralin (approximately 280 ng/l), which is less susceptible to ionization under atmospheric pressure conditions. At an enriched water volume of 10 ml, the whole SPE-HPLC-MS/MS procedure requires less than 14 min. The method was successfully applied to the analysis of drinking and surface water samples taken from several sampling sites around the city of Leipzig, Germany. Concentrations measured (maximum: 16 ng/l simazine in river water) were far below the concentration limits scheduled by law.