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PubMed2006

Exposure of young men to organochlorine pesticides in Southern Spain.

It has been hypothesized that endocrine disruptors and especially synthetic estrogenic environmental contaminants (xenoestrogens) are etiologic factors in the global decrease of sperm counts and other problems of the male reproductive tract, including cryptorchidism, hypospadias, and testicular cancer. This possibility has prompted research into the current and historical incidence of these diseases. The largest area of intensive greenhouse agriculture in Europe is near the Mediterranean coast of Southern Spain, where this activity has greatly expanded since the 1960s. We determined and compared levels of 14 organochlorine pesticides in the blood of 220 young males in Southern Spain. Aldrin, dieldrin, endrin, lindane, methoxychlor, endosulfans, and DDT and its metabolites were identified. Detectable concentrations of p,p'-DDE were found in 96% of serum samples. Among the remaining DDTs, o,p'-DDD was the most prevalent, detected in 65% of serum samples. Detectable concentrations of endosulfan I or II or their metabolites endosulfan-diol, or -sulfate were found in all samples; endosulfan-diol was the most frequently detected metabolite (92%) followed by sulfate. Results indicate that men of reproductive age in Southern Spain have been and are exposed to organochlorine pesticides. Because many of these chemicals have estrogenic and anti-androgenic activity, further research is warranted to interpret the male reproductive health consequences of this exposure.

Adult↗
PubMed2006

Evaluation of zirconocene-based silica phases in organochloride pesticides preconcentration.

Silica was chemically modified with zirconocenes, namely Cp(2)ZrCl(2), (MeCp)(2)ZrCl(2), (iBuCp)(2)ZrCl(2) and (nBuCp)(2)ZrCl(2) by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol-gel method, followed by metallation with ZrCl(4)2THF. According to RBS measurements, metal content was 0.2-0.3 wt% Zr/SiO(2) for the grafted systems and 4.5 wt% Zr/SiO(2) for the phase prepared by the sol-gel method. The solid phases were evaluated in the adsorption/preconcentration of organochloride (hexachlorobenzene, lindane, heptachlor, heptachlor epoxide, dieldrin and endrin) pesticides from aqueous solution. For comparative reasons, commercial LC-18 phase was also evaluated. Analyte concentration was monitored by GC-ECD. For the grafted phases, the coordination sphere around the metal center seems not to influence the adsorption/desorption properties of these phases vis-à-vis the studied analytes. Recoveries results for both analytes were comparable to those observed in the case of LC-18 in the case of the phases prepared by the sol-gel method. Experiments using ZrO(2) and ZrO(2)/SiO(2) phases led to lower recovery results.

Journal Article↗
PubMed2006

Distribution of organochlorine pesticides in surface water and sediments from Qiantang River, East China.

The levels of 13 organochlorine pesticides (OCPs) in surface water and sediments from Qiantang River in East China were investigated to evaluate their potential pollution and risks. A total of 180 surface water samples at 45 sampling sites and 48 sediment samples at 19 sampling stations were collected along the river in four seasons of 2005. Soil samples and wet deposition samples were also collected to provide evidence on the source of OCPs pollution. The total OCPs concentrations in surface water and sediments were 7.68-269.4 ng/L and 23.11-316.5 ng/g-dry weight (dw), respectively. The concentrations of OCPs in sediments were in the range of 8.22-152.1 ng/g-dw for HCHs (alpha-, beta-, gamma-, delta-HCH), 1.14-100.2 ng/g-dw for DDTs (p,p'-DDD, p,p'-DDE, p,p'-DDT o,p'-DDD), 9.41-69.66 ng/g-dw for other OCPs (aldrin, diedrin, endrin, heptachlor, heptachlor epoxide). The total OCPs concentrations in soils and wet deposition were 5.04-214.9 ng/g-dw and 16.18-242.4 ng/L, respectively. Among the OCPs, HCHs, DDTs and heptachlor were the most dominant compounds in the sediments. The dominant OCPs in water were gamma-HCH among HCHs, heptachlor among other OCPs and p,p'-DDE among DDTs. Also, different contamination patterns among sampling seasons were found. The concentrations of OCPs in sediment collected in spring were higher than those in summer and autumn. In contrast, the concentrations of OCPs in surface water in summer and autumn were higher among four sampling seasons. Distribution of HCHs, DDTs and other OCPs were different indicating their different contamination sources. The notable contamination was found in Fuchun reservoir. Composition analyses in sediments indicated a recent usage or discharge of lindane into the river.

China↗
PubMed2006

Activation of alpha- and beta-estrogen receptors by persistent pesticides in reporter cell lines.

Many persistent pesticides have been implicated in reproductive and developmental adverse effects, in man and wildlife. It has been hypothesized that these so-called xeno-hormones could upset the endocrine system function by binding to human estrogen receptor alpha and beta (ERalpha, beta) and thus be responsible for the higher incidence of breast and cervical cancer, infertility and endometriosis. In this report, forty-nine pesticides were tested for ERalpha and beta activation or inhibition in stable reporter cell lines, HELN ERalpha and ERbeta. Stable transfection of the ERalpha and ERbeta constructs together with an estrogen reporter luciferase vector into the HeLa cell line resulted in two estradiol-sensitive cell lines. In our model, fifteen of the tested pesticides were found to agonize the ERalpha-mediated transcription in a dose-dependent manner and DDT, trans-nonachlor, chlordane, fenvalerate and toxaphene were also capable to activate ERbeta. Antagonistic activities toward hERalpha and hERbeta were shown in three (carbaryl, pentachlorophenol and 2,4,5-trichlorophenoxyacetic acid) and seven (chlordecone, methoxychlor, carbaryl, endosulfan, endrin, dieldrin, aldrin) pesticides, respectively. Remarkably chlordecone and methoxychlor which were the most effective antagonist compounds for hERbeta, were agonists for hERalpha. Although the ERalpha activation potential of the pesticides was lower than that of estradiol, the overall body scale response might be amplified by the ability of pesticides to act via several mechanisms and by frequent and prolonged exposure to different pesticides, even at low concentrations.

Animals↗
PubMed2004

Organochlorinated compounds in Caspian Sea sediments.

Several organochlorinated contaminants, including numerous pesticides, were determined in coastal sediments from the Caspian Sea. The most important contaminants were p,p'-DDT (up to 7400 pg g(-1)) and its breakdown products, p,p'-DDD (up to 3400 pg g(-1)) and p,p'-DDE (up to 1300 pg g(-1)). Although the contamination was most severe in Azerbaijan, the sediment concentrations and percentage distribution of the three DDT-related compounds indicated that such contamination constitutes a contemporary and ubiquitous problem in the Caspian Sea. Lindane represented the second most significant contaminant, particularly in the Russian Federation, with concentrations up to 609 pg g(-1). The concentrations of HCB and other chlorinated pesticides (cis- and trans-chlordane, methoxychlor, heptachlor, heptachlor epoxide, aldrin, endrin, and endosulfans) were lower and not generally of concern, but the pesticides did demonstrate markedly different distributions reflecting differing agricultural usage in the region. The concentrations of Sigma PCBs were also quite low and ranged from 0.03 to 6.4 ng g(-1), with the highest amounts in the Russian Federation and Azerbaijan.

Agriculture↗
PubMed2005

Chlorinated hydrocarbons in marine biota and coastal sediments from the Gulf and Gulf of Oman.

The spatial distribution of various organochlorinated compounds was investigated in the Gulf and Gulf of Oman based on marine biota (fish and various bivalves) and coastal sediment collected in Bahrain, Oman, Qatar and the United Arab Emirates (UAE) during 2000-2001. Several potential organic contaminants from agricultural (e.g., DDT and its breakdown products, lindane, endrin, dieldrin, endosulfan) and industrial (PCBs) sources were measured. Sediment burdens for all compounds, even for an apparent hot spot near a refinery in Bahrain, were amongst the lowest reported for surface sediments from other seas. Concentrations of DDTs were low in the muscle and liver of all fish (orange spotted grouper and the spangled emperor) analysed. Similarly, the levels of chlorinated hydrocarbons were low in the various bivalve species, notably rock oysters and pearl oysters. These results contribute to the sparse regional database for organochlorinated compounds in the marine environment. Moreover, they can be used as the most recent end point for elucidating temporal trends. Whereas the levels, albeit relatively low, SigmaDDTs in the rock oysters from the Gulf of Oman have remained uniform, there has been an irregular but generally decreasing trend in concentrations of summation SigmaPCBs during the last two decades.

Animals↗
PubMed2004

Organochlorine pesticides and polychlorinated biphenyls in European roe deer Capreolus capreolus resident in a protected area in Northern Italy.

In 2001, samples of liver (n = 38) and perirenal fat (n = 25) (only in males) were taken from European roe deer (Capreolus capreolus) populating a hilly, wooded protected area in the Emilia-Romagna region of Northern Italy. Samples were analyzed for organochlorine pesticides dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), hexachlorocycloexane alpha-, beta- and gamma-isomers (alpha-, beta- and gamma-HCH), alpha-endosulfan, aldrin, dieldrin and endrin, and the seven PCB 'indicator' congeners IUPAC Nos. 28, 52, 101, 118, 138, 153 and 180, in order to investigate the current state of contamination of the area and to assess the possible toxicological risks for the monitored species. p,p'-DDE was detected in 95% of the liver and perirenal fat samples (n = 63), at concentrations ranging from < dl to 629.3 ng/g lipid weight, which were much higher than those found for HCB and gamma-HCH. The concentrations of the other measured organochlorine pesticides and metabolites were below the detection limit in all the samples. PCBs were found in 97% of the liver and perirenal fat samples, at total levels ranging between < dl to 414.5 ng/g lipid weight. The hepta- and hexa-chlorinated congeners 180, 153 and 138 were predominant and comprised more than 70% of the total seven PCBs in both the liver and perirenal fat samples. In the male roe deer, significantly higher concentrations of HCB, p,p'-DDE and PCBs were found in the liver than in the perirenal fat (P < 0.001). Hepatic levels of p,p'-DDE and PCBs were significantly higher in males than in females (P < 0.05 and P < 0.001, respectively). No significant differences in organochlorine concentrations were observed between juvenile and adult males in either tissue sample (P > 0.05). Females were not statistically tested because they were all adults. The levels of organochlorine contaminants were well below those associated with adverse reproductive effects and lethality in mammals.

Adipose Tissue↗
PubMed2004

Chlorobenzenes, chlorinated pesticides, coplanar chlorobiphenyls and other organochlorine compounds in Greenland biota.

This paper summarises the levels and composition of chlorobenzenes, chlorinated pesticides, coplanar polychlorinated biphenyls (PCBs) and the chlorinated compounds octachlorostyrene (OCS), hexachlorocyclobutadiene (HCBD) and pentachloro-anisole (PCA) in biota from the terrestrial, freshwater and marine environment of Greenland. The data were obtained during the second phase of the Arctic Monitoring and Assessment Programme (AMAP). Of the chlorobenzenes, hexachlorobenzene was the main constituent detected in almost all samples. The chlorobenzenes accumulate in the marine food web in a similar manner to the better-studied persistent organic pollutants, with maximum concentrations in beluga, minke whale and narwhal. However, concentrations in ringed seals and kittiwakes were lower than in marine fish, contradicting biomagnification. Of the organochlorine pesticides, the drin pesticides (aldrin, endrin, dieldrin) and heptachlor had increasing concentrations along the food chain, whilst biomagnification was less pronounced for endosulfan, methoxychlor and mirex. Endosulfan and methoxychlor are pesticides still in use and considered less persistent than other organochlorine pesticides. Their occurrence in Arctic biota is of particular concern, also given the high acute toxicity of endosulfan to fish. Chlorobenzene and pesticide concentrations tended to be lower in the Greenland samples than in the same animals from the Canadian Arctic, whilst their concentrations were similar to samples from Svalbard and Iceland. However, temporal trends might overlap the geographical differences. Coplanar chlorobiphenyls (CBs) were found in all samples analysed, with the maximum concentrations found in marine mammals such as beluga and narwhal. Biota from the terrestrial environment appeared to be less contaminated. The main contributor on a TEQ basis was CB126. OCS, HCBD and PCA were detected in biota from Greenland, although at very low concentrations. OCS seems to have the widest occurrence and the highest potential for biomagnification of the three compounds analysed.

Animals↗
PubMed2005

Organochlorines (PCBs and pesticides) in the bivalves Anadara (Senilis) senilis, Crassostrea tulipa and Perna perna from the lagoons of Ghana.

The bivalves, Anadara (Senilia) senilis (n=95), Crassostrea tulipa (n=75) and Perna perna (n=30) from Ghana, were analyzed for their organochlorines (pesticides and PCBs) concentrations and the body burden. A comparison was done based on two different standard PCB mixtures (Aroclor 1254 and 1260) with the percentage individual congener contribution and that of the sample. From these comparisons, it appeared that the pattern of PCB residues in the samples was neither Aroclor 1254 nor 1260. On the other hand, there was seasonal qualitative difference in the pattern that is purely marine (in the dry season) versus terrestrial input (in the wet season). SigmaPCB was 0.10 microg/g dw or 2.2 microg/g lw (median values). There was no correlation between PCB concentration and lipid content reflecting the importance of indirect contamination of the bivalves. The pesticides, aldrin, dieldrin, endrin, lindane, DDTs, HCH, HCB, endosulfan, heptachlor epoxide and heptachlor, were detected. The most abundant pesticides were the SigmaDDT: 73 and SigmaHCH: 29 ng/g dw. DDT/DDE and hept./heptachlor epoxide ratios reflect their recent applications, while the ratio for aldrin/dieldrin suggests that the use of aldrin has been discontinued, at least on the coast of Ghana.

Animals↗
PubMed2006

Metals and organochlorine pesticides in caudal scutes of crocodiles from Belize and Costa Rica.

Despite high animal diversity in the Neotropics and the largely unregulated use and disposal of pesticides and industrial chemicals in Central America, few data exist regarding accumulation of environmental contaminants in Central American wildlife. In this study we examined accumulation of metals and organochlorine (OC) pesticides in caudal scutes of crocodiles from Belize and Costa Rica. Scutes from Morelet's crocodiles (Crocodylus moreletii) from two sites in northern Belize were analyzed for metals, and scutes from American crocodiles (C. acutus) from one site in Costa Rica were analyzed for metals and OC pesticides. All scutes (n=25; one scute from each of 25 individuals) contained multiple contaminants. Mercury was the predominant metal detected, occurring in all scutes examined from both species. Other metals detected include cadmium, copper, lead, and zinc. American crocodile scutes from Costa Rica contained multiple OC pesticides, including endrin, methoxychlor, p,p'-DDE, and p,p'-DDT, all of which occurred in 100% of scutes analyzed (n=6). Mean metal and OC concentrations varied in relation to those previously reported in crocodilian scutes from other localities in North, Central, and South America. OC concentrations in American crocodile scutes were generally higher than those previously reported for other Costa Rican wildlife. Currently, caudal scutes may serve as general, non-lethal indicators of contaminant accumulation in crocodilians and their areas of occurrence. However, a better understanding of the relationships between pollutant concentrations in scutes, internal tissues, and environmental matrices at sample collection sites are needed to improve the utility of scutes in future ecotoxicological investigations.

Alligators and Crocodiles↗
PubMed2005

Activation of retinoic acid receptor-dependent transcription by organochlorine pesticides.

Five organochlorine pesticides, namely, chlordane, dieldrin, aldrin, endrin, and endosulfan, activate human retinoic acid receptor (RAR)-mediated gene transcription via a retinoic acid response element (RARE). Transactivation studies were performed with stable RARalpha, beta, or gamma reporter cell lines in which the RAR DNA-binding domain (DBD) was replaced by that of estrogen receptor alpha (ERalpha)? Five of the organochlorine pesticides tested activated RARbeta and RARgamma but not RARalpha; their half-maximal luciferase activity (EC(50)) was determined. Furthermore, that activity was RAR-specific and organochlorine pesticides did not activate the retinoid X receptor (RXR) pathway. However, competitive binding experiments with [(3)H]-CD367, a pan-RAR agonist, showed that only chlordane could bind RARbeta and RARgamma, albeit with low affinity. In addition, organochlorine pesticides strongly induce cytochrome P450RAI1 (P450RAI1), a key factor of retinoic acid level regulation in many tissues and whose expression and activity are strongly induced by retinoic acid. This study shows that organochlorine pesticides can activate two RAR homologues, with low-binding affinity. Although the agonistic potential of organochlorine pesticides is lower than that of (E)-4-[2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1-propenyl] benzoic acid (TTNPB), they are able to induce RAR-mediated gene transcription as P450RAI1 and may disrupt the retinoid signaling pathway. Because these chemicals are extremely persistent and tend to accumulate in biological tissues, these results support the hypothesis that the increase in teratogenicity observed in some developing countries could be due to prolonged exposure to organochlorine pesticides ubiquitously present in the environment.

Animals↗
PubMed2004

Persistent organic pollutants (POPs) in the sewage treatment plant of Thessaloniki, northern Greece: occurrence and removal.

The occurrence and the removal of persistent organic pollutants (POPs) during the conventional activated sludge treatment process were investigated in the wastewater treatment plant of the city of Thessaloniki, northern Greece. POPs of interest were seven polychlorinated biphenyls (PCBs) and 19 organochlorine pesticides. Target compounds were determined at six different points across the treatment system. Most abundant compounds in raw wastewater at all treatment stages were PCB-52, PCB-110, PCB-180 and Heptachlor-exo-epoxide. Quintozene occurred frequently but in relatively low concentrations. Hexachlorocyclohexanes, DDT and its metabolites (DDE, DDD) and Aldrin, Dieldrin, Endrin, Isodrin ("Drins") were found at medium or low frequencies and in concentrations close to their detection limits. Removal percentages throughout the whole treatment process ranged from 65% to 91% for individual POP species. Significant linear relationship was observed between removal efficiency and log Kow for PCBs suggesting that compounds with a strong hydrophobic character are principally removed through sorption to sludge particles and transfer to the sludge processing systems. Total PCBs' concentrations in sewage sludge ranged between 185 and 765 ng g(-1) dw being below the EU limit for use of sludge in agriculture.

Environmental Monitoring↗
PubMedDate not supplied

Extraction and clean-up procedure for analysis of organochlorine pesticide residues in ethoxylated lanolin.

In the present study an evaluation was made of a method for the determination of organochlorine pesticide residues in ethoxylated lanolin. Samples were homogenized with Celite, transferred to chromatographic columns, prepacked with silica gel deactivated to 10%. The pesticide elution was processed with n-hexane-dichloromethane and the concentrated eluate was analyzed using gas-liquid chromatography (GC) with electron capture detection (ECD). The composition of the elution solvent was a significant factor for the recovery of the pesticides. Mean recoveries obtained for fortified samples ranged from 87 to 94% for p,p'-DDE, dieldrin, endrin, p,p'-DDD and p,p'-DDT. Optimization of the experimental conditions resulted in a small-scale method that combines extraction and cleanup in a single step.

Animals↗
PubMed1977

Determination of chlorinated pesticides in potable water.

A procedure is described for monitoring organochlorine pesticides in potable water. Material adsorbed from water on to Amberlite XAD-2 macroreticular resin was eluted with n-hexane and the concentrated eluate was analyzed without further treatment. Electron capture (63Ni) gas chromatography utilizing a column of 4% QF-1 and 2% SE-30 on 80-100 mesh HP Chromosorb W at 180 degrees permitted identification of organochlorine pesticides and indicated the presence of phthalates. Confirmatory qualitative and quantitative analyses were done by specific ion-monitoring mass spectrometry. Levels determined in Ottawa drinking water were 17 ppt alpha-BHC, 1.3 ppt lindane, 0.7 ppt aldrin, and less than 0.05 ppt for each of heptachlor, heptachlor epoxide, dieldrin, endrin, chlordane, o,p'-DDT, p,p'-DDD, p,p'-DDT, and p,p'-DDE.

Chromatography, Gas↗
PubMed1991

Simultaneous separation and determination of hydrocarbons and organochlorine compounds by using a two-step microcolumn.

The simultaneous separation and determination of a mixture of hydrocarbons and organochlorine compounds was successfully carried out by using sorption chromatography on a two-step microcolumn of silica and aluminium oxide for their fractionation, and a dual detector system. In addition to the separation and identification of hydrocarbons and heterocompounds containing nitrogen, oxygen and sulphur atoms, separation and identification of chlorinated hydrocarbons (dichlorobenzenes, p-chlorotoluene, hexachlorobutadiene, 1,2,4-trichlorobenzene and 2-chloronaphthalene), pesticides (chlorpicrin, aldrin, lindane, alpha- and beta-benzene hexachloride (BHC), endrin, dieldrin, endosulphan, methoxychlor) and herbicides (propanil, dichlobenil, trifluralin, difolatan) were achieved in mixtures containing polychlorinated biphenyl, strobane and chlordane.

Chromatography↗
PubMed2002

Determination of organochlorine pesticides in ground water using solid-phase microextraction followed by dual-column gas chromatography with electron-capture detection.

A rapid, sensitive, convenient, and highly quality-assured method is presented for the determination of 19 organochlorine pesticides (OCPs) in small samples (10 ml) of ground water. Samples are initially fortified with 2,4,5,6-tetrachloro-m-xylene (surrogate) and decachlorobiphenyl (retention time marker), then extracted with a 30-micron thickness polydimethylsiloxane solid-phase microextraction fiber. The analytes collected are thermally desorbed in a heated gas chromatographic inlet, separated using independent fused-silica capillary columns ("primary" and "confirmatory"), and detected using electron-capture detection. Two independent statistical procedures were used to evaluate the detection limits, which typically range between 10 and 40 ng l-1, for these analytes. Method performance was also evaluated using two additional protocols employing "performance evaluation" samples, in which authentic ground water samples were fortified to ca. 100 ng l-1 in each of at least six OCPs. The method satisfies additional strict criteria based on uniformity of fiber performance and minimal degradation of the thermally-sensitive analytes endrin and DDT.

Calibration↗
PubMed2003

Methods for selective determination of persistent organochlorine pesticide residues in water and sediments by capillary gas chromatography and electron-capture detection.

Different extraction methods were evaluated for the determination of fifteen organochlorine pesticides (OCPs) in water and sediments. Liquid-liquid extraction (LLE) was evaluated for the pesticides analyses in water while Soxhlet extraction (SE) and microwave assisted extraction (MAE) methods were compared in sediment. Of all the extracting solvents used, dichloromethane gave the best results. Percentage recoveries ranged from 71.03 +/- 8.15 (dieldrin) to 101.25 +/- 2.17% [a-benzenehexachloride (alpha-BHC)] in water with LLE. In sediments the percentage recoveries with Soxhlet extraction method varied between 88.22 +/- 7.85 (endrin) and 109.63 +/- 5.10% (beta-BHC) and ranged from 74.11 +/- 9.82 (2,4 DDT) to 97.50 +/- 4.56% (alpha-BHC) with MAE. The limits of detection for the OCPs ranged from 5.5 to 20.6 ng/l and between 0.6 and 2.1 ng/g. respectively. The LLE and the SE methods were applied to water and sediments samples, respectively, from marine and freshwater sources in the Eastern Cape Province of South Africa that receive runoffs from agricultural lands and effluents from industries. The levels of OCPs ranged from 5.5 (2,4-DDD) to 450 +/- 0.10 ng/l (beta-BHC) in water samples and from 0.6 (aldrin and 2,4-DDD) to 184 +/- 0.12 ng/g (beta-BHC) in sediments for triplicate analyses. Some endocrine disrupting OCPs such as DDT, DDE, heptachlor, endosulphan and the chlordanes were detected.

Chromatography, Gas↗
PubMed2003

Screening and determination of pesticides in soil using continuous subcritical water extraction and gas chromatography-mass spectrometry.

In the present work the efficiency of water under subcritical conditions for the extraction of pesticides having a broad spectrum of polarities from soils was evaluated. The pesticides under study were carbofuran, hexachlorobenzene, dimethoate, simazine, atrazine, lindane, diazinon, methylparathion, alachlor, aldrin-R, metholachlor, chlorpyrifos, heptachlor epoxide, dieldrin, endrin, 4,4-DDT and metoxichlor. Optimization studies were carried out using a blank soil (Non-Polluted Soil 1, CLN-1, RTC) and a real soil which were previously spiked with the pesticide mixture and aged for 60 days. A laboratory-made aluminum oven with controlled temperature was used to carry out the leaching process with subcritical water, where it is placed a pre-heater and the extraction cell. The following variables were studied, keeping the pressure controlled about 1200 p.s.i.: the extraction temperature, the time of static and dynamic extraction and the flow-rate of water (1 p.s.i. = 6894.76 Pa). The extraction efficiency of the pesticides increases with the temperature trending to the quantitative extraction at temperatures near to 300 degrees C. After the extraction process, the analytes were transferred quantitatively to 5 ml dichloromethane, before the determination by GC-MS. The results indicate that under the optimized conditions mostly of the analytes are extracted quantitatively in 90 min with recoveries quite similar to those obtained by the standard Soxhlet extraction procedure. Alternatively, by using an extraction time of 25 min, the method can be used as screening for all the pesticides, with recoveries depending on their polarity.

Gas Chromatography-Mass Spectrometry↗