Residual Organochlorine Pesticides Research Articles

Evaluating bottle liquid-liquid extraction technique for monitoring residual levels of organochlorine pesticides in wastewater treatment-associated matrices

The gold standard for recovering residual organochlorine pesticides from wastewater and aqueous environmental matrices is the continuous liquid-liquid extraction (CLLE) technique that requires methylene chloride (CH2Cl2) as solvent at its refluxing temperature. In light of a recent USEPA proposed prohibitions and workplace protections for CH2Cl2 (due to its toxicity) and the fact that CLLE requires expensive and hard-to-acquire glassware, an alternative to CLLE as currently practiced is needed. The bottle liquid-liquid extraction (BLLE) technique, demonstrated for extracting semi-volatile organic contaminants from surface water, is potentially a low cost and high throughput alternative for such recovery. BLLE is cheaper and has a smaller laboratory footprint. The technique, performed at ambient temperature in a tightly capped bottle, requires less amount of solvent and contains solvent vapor within the bottle. The latter means less CH2Cl2 is encountered in the workplace. In this study, BLLE was performed directly in 1-L amber sampling bottles and shown to recover 21 organochlorine pesticides as efficiently as CLLE from influents and effluents of two wastewater treatment plants Because no statistical differences were found between CLLE (mean = 77.4, SD = 9.28) and BLLE (mean = 79.1, SD = 14.3); t(22) = 0.548, p(same mean) = 0.58, even though CLLE recovered more pesticides than BLLE by 5.18 ± 8.15%, these techniques are amenable to interchangeable usage. The systematic bias so far detected fits the expression BLLE = 1.4[CLLE] – 35 (r = 0.88). Both CLLE and BLLE recoveries were consistently higher for 4,4′-DDD and lower for aldrin, heptachlor and endrin aldehyde. Diethyl ether addition, as some suggested, did not improve BLLE.Synopsis: There is need to find a cheap, reliable and high throughput technique for purifying SVOCs from aqueous environmental media efficiently. BLLE, a little known technique, fulfils this need.

Temporal trends, sources, and ecological risk of residual organochlorine pesticides (OCPs) in sediment core from the Dongping Lake, North China.

A sedimentary record of the 19 organochlorine pesticides (OCPs) pollutants from Dongping Lake, north China, is presented in this study. According to the dating of core sediment and OCP content analysis in samples, from 1904 to 2016, the total concentration of OCPs varied from undetectable levels (n.d.) to 33.1ng/g. The OCP concentration was first detected in the samples of 1938, and then gradually increased to a peak level in 2000 thereafter decreased until 2016. Among the detected OCPs, hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were the predominant and the most frequently detected contaminants in the core sediment, with concentrations ranging from n.d. to 16.9ng/g and from n.d. to 8.8ng/g, respectively. The distribution of OCPs in the sediments was affected by organic carbon concentration, showing a significant positive correlation (r = 0.93, p < 0.001), especially for HCHs (r = 0.98, p < 0.001). The source analysis showed that HCH contamination mainly derived from historical use of technical HCHs, while in recent years, it derived from lindane usage. DDT pollution was attributed to historical use of technical DDTs, as well as the microbial degradation of historic DDT residues. Finally, risk analysis was performed for OCPs in sediment cores based on sediment quality guidelines from the Canadian Council of Ministers of the Environment, showing that DDTs presented a high ecological toxicity risk during the period of 1959-2010.

Pollution Characteristics and Health Risk Assessment of Halogenated Organic Pollutants (HOPs) in Fish from the Laibin Section of Hongshui River, China

This study used gas chromatograph-mass spectrometer (GC-MS) to determine three kinds of halogenated organic pollutants (HOPs) in the edible muscles of nine fish species in the Laibin section of the Hongshui River of Xijiang River in the Pearl River system. The results showed that the sum of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in fish muscle was 8.94∼43.32 ng/g ww, 1.22∼4.09 ng/g ww, and ND∼0.13 ng/g ww, respectively. Evaluation indicators include analysis of the composition of homologous compounds, residues in different diets and habitats, and estimated daily intake (EDI) calculations. The analysis of the composition characteristics of homologous compounds showed that endrin was the most dominant in OCPs; hexachlorobenzene was the most dominant in PCBs; and BDE 154 was the most dominant PBDEs. Calculations of the levels of the HOPs in fish of different diets and habitats showed that OCPs and PCBs had the highest residues in carnivorous fish, and PBDEs had the highest residues in herbivorous fish. The residual OCPs, PCBs, and PBDEs in demersal fishes were the most. The estimated daily intake (EDI) results showed that daily fish consumption in the Laibin section of the Hongshui River would not cause HOPs health risks to the local residents. However, there is still a need for continuous monitoring of HOPs to reduce pollutant emissions and prevent pollution conditions from arising.

Quantification of Residual Organochlorine Pesticides in Medicinal Plant Raw Materials Containing Terpenoids

An important indicator of the safety of plant raw materials and herbal medicinal products is the content of residual pesticides. Its determination is particularly difficult in aromatic plants characterised by a diverse composition of terpenoids co-extracting with organochlorine pesticides and forming numerous degradation products that interfere with the analysis.The aim of the study was to develop and validate an analytical procedure for the quantification of organochlorine pesticides in plant raw materials containing terpenoids, compliant with the requirements of the State Pharmacopoeia of the Russian Federation.Materials and methods: the study analysed samples of morphologically different raw materials from 21 plant species containing terpenoids. The analysis was carried out by GLC-MS on a 450-GC gas chromatograph coupled to a 220-MS ion-trap mass spectrometer (Varian, USA) using a FactorFour VF-5ms quartz capillary column (30 m × 0.25 mm).Results: the authors developed the analytical procedure for organochlorine pesticides in medicinal plant raw materials containing terpenoids. Its specificity was confirmed by retention times and mass spectra for all the tested analytes. The recovery of pesticides was studied on model mixtures of a plant raw material and ranged from 70.04 to 99.27%. The authors established the linearity using a calibration curve for internal standard (4,4'-dibromodiphenyl) concentrations from 1.0 to 18.1 µg/mL. The procedure was linear across the entire studied range; the correlation coefficient equalled 0.999. The trueness and precision of the analytical procedure met the acceptance criteria.Conclusions: the analytical procedure has been put into use at the Testing Centre of VILAR. From 2018 to 2020, 63 samples of 21 types of medicinal plant raw materials were analysed and found to be corresponding to the safety requirements for the organochlorine pesticide content. Residual pesticides were detected in the medicinal plant raw materials in few sporadic cases.

Qualitative assessment of residual organochlorine pesticide in staple foods consumed in Wukari, Taraba State

This study was aimed to determine the residual organochlorine presence in some staple foods; Yam (Dioscorea spp) and Bambara nut (Vigna subterranean) sold in Wukari markets. Samples were randomly collected from three major markets across the study areas. Representative samples were cleansed, dried, pulverized and sieved. Extractions were determined using standard analytical techniques while residual organochlorine pesticides were determined using GCMS. The detected organochlorine pesticide residues in yam were Dichlorodiphenyltrichloroethane (DDT), heptachlor, dieldrin, toxaphene and Dichlorodiphenyldichloroethane (DDE) while those detected in Bambara nut were 1, 4dichlorobenzene, methoxychlor, pentachlorophenol, DDT, and toxaphene. This preliminary assessment showed that Yam and Bambara nut consumed in Wukari contained certain level of organochlorine pesticide residues which may be detrimental to human health in the nearest future.

Vertical distribution and effect of historical residual organochlorine pesticides on microbial community structure in sediment cores from an abandoned oxidation pond after dredging for 15 years.

The vertical distribution pattern of 19 organochlorine pesticides (OCPs), together with microbial ester-linked fatty acid methyl ester (EL-FAME) profiles were investigated in sediments from an abandoned oxidation pond of Ya-Er lake, China, which had been heavily polluted by hexachlorocyclohexanes (HCHs) and chlorobenzenes in 1980s. Subsurface sediment samples were taken from five sediment cores along the transect running from the lakeshore (0.5~2.7 m in depth) to lakebed (0.1~0.4 m). The total OCP concentration ranged from 29.8 to 941.8 ng g-1 dw. Hexachlorobenzene (HCB), HCHs, and dichlorodiphenyl-trichloroethanes (DDTs) were the three dominant OCP classes, accounting for 26.5-97.4%, 1.8-33.2%, and 0.4-15.5% of the total OCP concentration, respectively. Hot spots of HCB, HCHs, and DDTs were detected at 0.9~2.7 m deep layers of the lakeshore, where was oncethe maindredged sediment backfill site for in-situ remediation of the oxidation pond in 2002-2004. HCHs and HCBstill showed high potential ecological risks. The sources of OCPs were identified and quantified using principal component analysis with absolute principal component scores-multiple linear regression model. The firstthree major sources were persistent residues, recent agricultural input, and historical industrial input, contributing on average 28.2%, 17.9%, and 17.1% of total OCPs, respectively. Redundancy analysis of microbial EL-FAME profiles and nine dominant OCPs revealed that the spatial variation in microbial community structure was significantly corresponded with the OCP composition. This is the first study highlighting the concern on historical industrial inputs of OCPs in subsurface sediments of the lakeshore disposal zone. The findings could help to distinguish the artificial backfill sediments from undisturbed polluted sediments for optimization of further dredging plans.

Sorption of organochlorine pesticides on polyethylene microplastics in soil suspension

As a new type of environmental pollutant, microplastics (MPs) can adsorb residual organochlorine pesticides (OCPs) in the soil and pose a severe threat to the soil ecosystems. To understand the interaction between soil MPs and OCPs, the sorption of two kinds of OCPs, including hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs), on polyethylene (PE) microplastics in soil suspension was studied through sorption kinetics and isotherm models. The effects of solution/soil ratio and MPs diameter on sorption were examined. The kinetic experiment results show that the sorption equilibrium was 12 h， and the sorption process of OCPs on MPs can be well described by a pseudo-second-order model. The Freundlich model (R2 = 0.942–0.997) provides a better fit to the sorption isotherm data than the Langmuir model (R2 = 0.062–0.634), indicating that the sorption process takes place on the nonuniform surface of MPs. The MPs had a good sorption effect on OCPs when the solution/soil ratio was from 75:1 to 100:1. As the diameter of MPs increases, the sorption capacity decreases. These results provide support for further research on microplastic pollution in soil.

Residual organochlorine pesticides in the salad vegetables cultivated in Lagos, Nigeria and their human health risks

Concerns are mounting over the health risks associated with the use of harmful pesticides to control crop pests. In this study, the salad vegetables and soil samples from three farms in Lagos, Nigeria were evaluated for organochlorine pesticide residue concentrations using gas chromatography-mass spectrometry (GC-MS). Eighteen organochlorine pesticides were detected in the vegetable and soil samples. In Idi-Araba farm, α-BHC had the highest concentration (0.06±0.07 mg/kg) in lettuce shoots, Endosulfan I had the highest concentration (0.29±0.26 mg/kg) in spring onion. P, P-DDE and L-cyhalothrin had the highest concentrations (0.08±0.03 and 0.08±0.08 mg/kg, respectively) in spinach shoots. In Tejuosho farm, L-cyhalothrin, PF-38, and chlorothalonil had the highest concentrations (0.50±0.71, 0.13±0.07, and 0.03±0.01 mg/kg, respectively) in lettuce shoots, spring onions, and spinach, respectively. In Alapere farm, Endosulfan I had the highest concentration (0.03±0.02 mg/kg) in lettuce shoots, Aldrin had the highest concentration (0.02±0.01 mg/kg) in spring onion shoots, and L-cyhalothrin had the highest concentration (0.04±0.05 mg/kg) in spinach shoots. The concentrations of these pesticides were higher than the maximum residual limit prescribed by the European Union (EU) Commission. Moreover, the hazard index (HI) calculated for spring onion and spinach from Idi-Araba farm and lettuce from Tejuosho farm exceeded one (HI>1). These results may be a reflection of what obtains in other countries where harmful pesticides are still being used. Therefore, governments and stakeholders should raise awareness to discourage farmers from the use of organochlorines and other harmful pesticides.

Spatial Distribution and Ecological Risk Assessment of Residual Organochlorine Pesticides (OCPs) in South American Marine Environments.

Organochlorine pesticides (OCPs) have been intensely used and produced in South America. Although they were banned before the year 2000 (excepting endosulfan, which has been recently banned in several countries), OCPs remain detectable in marine environments of this continent, sometimes at risky levels for biota. This manuscript summarizes studies on OCP levels in the air, water, sediment, bivalves, fish, and marine mammals of the South American coasts and open waters over the last 20years, tackling their spatial distribution and analyzing their associated ecotoxicological risk. To the best of our knowledge, this is the first study integrating all available information on current levels of OCPs in South American marine environments. The 63 researches reviewed studied punctual sites or environmental compartments. The OCP levels were higher in semi-enclosed environments such as bays and estuaries, close to large cities. In terms of individual OCPs, dichlorodiphenyltrichloroethane (DDT) and its degradation products were more abundant than other OCPs in all the environmental compartments, excepting air, for which the most abundant OCP was endosulfan. Depending on the location and the environmental matrix, hexachlorocyclohexanes (HCHs), heptachlors, mirex, and endosulfans followed DDTs. Aldrin, dieldrin and endrin, hexachlorobenzene (HCB), and chlordanes were found at very low levels in most matrices and sites, with some exceptions. Considering their potential ecotoxicological risk, most sites would be safe for biota; however, the levels of some OCPs could damage the structure and function of the communities of several coastal sites in a short or long term, mainly in southeastern Brazil and on the coast of the Argentine Pampas. Moreover, it remains to evaluate many sites potentially contaminated by OCPs.

사과 및 배 과수원의 토양 및 과실 중 잔류성유기염소계 농약류 잔류량 조사

사과 및 배 과수원의 토양 및 과실 중 잔류성유기염소계 농약류 잔류량 조사

포도 및 복숭아 과수원 토양 및 과실 중 잔류성유기염소계 농약류 잔류량 조사

본 연구에서는 포도 및 복숭아 과수원 토양 및 과실 중 잔류성유기염소계 농약류의 잔류량을 조사하였다. 과수원 토양 및 과실 중 잔류성유기염소계 농약 분석을 위한 추출 및 정제는 QuEChERS 방법을 다소 개선한 방법으로 수행되었다. 과수원 토양 및 농산물 중 잔류성유기염소계 농약류의 회수율은 각각 76.4-101.2 및 76.4-90.4%, 검출한계는 각각 0.01-0.08와 0.2-0.4 mg/kg 수준이었다. 과수원 토양에서 2,4-DDT, 4,4-DDE, 4,4-DDT 및 endosulfan sulfate 4개 성분만이 각각 3.3, 2.3-7.1, 4.5 및 19.2-73.4 mg/kg 수준으로 검출되었으나 모든 과실시료에서는 검출되지 않았다. 이러한 결과는 포도 및 복숭아 과수원 토양이 농산물 안전성을 위협할 정도로 잔류성유기염소계 농약으로 오염되지 않았음을 나타냈다.

Occurrences and patterns of residual organochlorine pesticides (OCPs) in cultured Chinese mitten crab (Eriocheir sinensis) in China: concentrations, sources, and a human health risk assessment.

Seventy Chinese mitten crab samples, encompassing a total of 2100 individuals, were collected from the main production areas in China. The objective was to assess the occurrences and patterns of 23 selected organochlorine pesticides (OCPs) in the edible tissues and assess the associated dietary risk. Concentrations of total residual OCPs in the mitten crabs ranged from 0.72 to 51.51μgkg-1, which was comparable to other global aquatic species. Dichlorodiphenyl trichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) were the two main contributors of total OCPs, with the detected values ranging from 0.14 to 30.89μgkg-1 and 0.23 to 4.04μgkg-1, respectively. Source analysis indicated the coexistence of both residual and recent DDT inputs, while there was no indication of HCH usage in the main production area of mitten crab. In terms of dietary risk, at least eight individual mitten crabs per day are permissible for consumption by local residents, indicating low risk from consumption. The results presented herein should guide the production and consumption of mitten crab, as well as promote the sustainable development of aquaculture in China.

Tracking residual organochlorine pesticides (OCPs) in green, herbal, and black tea leaves and infusions of commercially available tea products marketed in Poland

ABSTRACTThe content of residual organochlorine pesticides (OCPs) was examined in green, herbal, and black tea leaves as well as in their infusions prepared from tea products marketed in the main supermarkets in Poland. It was found that the detected mean levels of organochlorine residues in tea leaves ranged from <LOD to 16.36 ng g−1 dry weight. Among hexachlorocyclohexane isomers, γ-HCH in green tea occurred in the highest concentrations. Among dichlorodiphenyltrichloroethane (DDT) metabolites the highest level of p,p′DDT (1.96 ng g−1 dw) was in green tea samples. The transfer of OCPs from tea leaves to brew was investigated. The present study revealed that during the infusion process, a significant percentage of the residues, particularly pesticides with high water solubility, were transferred to the infusions. The obtained results show that the percentage transfer of each pesticides from tea to the tea infusions ranged from 6.74% (heptachlor) to 86.6% (endrin). The detected residues were below current MRLs for these pesticides.

딸기 시설재배지 토양 및 농산물 중 잔류성유기오염물질(POPs)의 잔류량 &amp;#8211; 유기염소계 농약

BACKGROUND: Residual organochlorine pesticides (OCPs) are chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effect to human health and the environment. They were designated as persistent organic pollutants (POPs) by Stockholm Convention. Greenhouse strawberry is economic crop in agriculture, and its cultivation area and yield has been increased. Therefore, we tried to investigate the POPs residue in greenhouse soil and strawberry.METHODS AND RESULTS: Extraction and clean-up method for the quantitative analysis of OCPs was developed and validated by gas chromatography (GC) with electron capture detector (ECD). The clean-up method was established using the modified quick, easy, cheap, effective, rugged, and safe(QuEChERS) method for OCPs in soil and strawberry. Limit of quantitation (LOQ) and recovery rates of OCPs in greenhouse soil and strawberry were 0.9-6.0 and 0.6-0.9 μg/kg, 74.4-115.6 and 75.6-88.4%, respectively. The precision was reliable sincerelative standard deviation (RSD) percentage (0.5-3.7 and 2.9-5.2%) was below 20, which was the normal percent value. The residue of OCPs in greenhouse soil was analyzed by the developed method, and dieldrin, β-endosulfan and endosulfan sulfate were detected at 1.6-23, 2.2-28.4 and 1.8-118.6 μg/kg, respectively. Those in strawberry were not detected in all samples.CONCLUSION: Dieldrin, β-endosulfan and endosulfan sulfate in a part of investigated greenhouse soil were detected. But those were not detected in investigated greenhouse strawberry. These results showed that the residue in greenhouse soil were lower level than bioaccumulation occurring.

Dynamics of the microbial community and Fe(III)-reducing and dechlorinating microorganisms in response to pentachlorophenol transformation in paddy soil

Soil microorganisms play crucial roles in the fates of pollutants, and understanding the behaviour of these microorganisms is critical for the bioremediation of PCP-contaminated soil. However, shifts remain unclear in the community structure and Fe(III)-reducing and dechlorinating microorganisms during PCP transformation processes, especially during the stages from the lag to the dechlorination phase and from the dechlorination to the stationary phase. Here, a set of lab-scale experiments was performed to investigate the microbial community dynamics accompanying PCP transformation in paddy soil. 19μM of PCP was biotransformed completely in 10days for all treatments. T-RFLP analysis of the microbial community confirmed that Veillonellaceae and Clostridium sensu stricto were the dominant groups during PCP transformation, and the structures of the microbial communities changed due to the degree of biotransformation and the addition of lactate and AQDS. However, similar temporal dynamics of the microbial communities were obtained among all treatments. Furthermore, as revealed by quantitative PCR, the dynamics of Fe(III)-reducing and dechlorinating microorganisms, including Geobacter sp., Shewanella sp., and Dehalobacter sp., were consistent with the transformation kinetics of PCP, suggesting the critical roles played by these microorganisms in PCP transformation. These findings are valuable for making predictions of and proposing methods for the microbial detoxification of residual organochlorine pesticides in paddy soil.

Evaluation of pesticide residue analysis of dieldrin in soil using a high resolution gas chromatograph/mass spectrometer (HR-GC/MS)

The objective of this study was to evaluate the effectiveness of using HR-GC/MS for the rapid screening of dieldrin residues in soils. Persistent organic pollutants (POPs) of organochlorine pesticides such as dieldrin, were analyzed in sedimentary rock and granite rock collected from greenhouses, Niigata, Japan. Dieldrin remains in Japanese farming soils, more than 40 years after their use as insecticides was prohibited. The averages in soil moisture ranged from 2.79% to 7.20% in soils derived from sedimentary rock and from 25.59% to 31.40% in soils derived from granite rock. Mean concentrations of dieldrin residues in sedimentary rock and granite rock were 39.7 ng g-1 and 40.51 ng g -1 , respectively. Dieldrin residue was detected at a slightly higher concentration in granite rock than sedimentary rock samples. There was no consistency between the two soils or between surface and subsurface soils. The coefficients of variation of the two soils were 10.6% and 8.7%, respectively. These results suggest that our high-resolution mass spectrometry detector (HR-GC/MS) is effective at analyzing residual organochlorine pesticides in soil. In order to increase the precision and sensitivity for chemical analysis of POPs, high-resolution gas chromatography coupled with a HR-GC/MS is highly recommended.

Spatial distribution, source apportionment and ecological risk assessment of residual organochlorine pesticides (OCPs) in the Himalayas.

The Indian Himalayan Region (IHR) is one of the important mountain ecosystems among the global mountain system which support wide variety of flora, fauna, human communities and cultural diversities. Surface soil samples collected from IHR were analysed for 23 organochlorine pesticides (OCPs). The concentration of ∑OCPs ranged from 0.28 to 2143.96 ng/g (mean 221.54 ng/g) and was mostly dominated by DDTs. The concentration of ∑DDTs ranged from 0.28 to 2126.94 ng/g (mean 216.65 ng/g). Other OCPs such as HCHs, endosulfan and heptachlor, Aldrin and dieldrin were detected in lower concentration in IHR. Their concentrations in soil samples ranged from ND to 2.79 ng/g for HCHs, ND to 2.83 ng/g for endosulfans, NDto 1.46 ng/g for heptachlor, ND to 2.12 ng/g for Aldrin and ND to 1.81 ng/g for dieldrin. Spatial distribution of OCPs suggested prevalence of DDTs and HCHs at Guwahati and Itanagar, respectively. The close relationship between total organic carbon (TOC) and part of OCP compounds (especially α- and γ-HCH) indicated the important role of TOC in accumulation, binding and persistence of OCP in soil. Diagnostic ratio of DDT metabolites and HCH isomers showed DDT contamination is due to recent application of technical DDT and dicofol, and HCH contamination was due to mixture of technical HCH and lindane source. This was further confirmed by principal component analysis. Ecological risk analysis of OCP residues in soil samples concluded the moderate to severe contamination of soil.

Characteristics of residual organochlorine pesticides in soils under different land-use types on a coastal plain of the Yellow River Delta.

The residual levels of organochlorine pesticides (OCPs) were examined in soils covering five types of land use along a salinity gradient on the Yellow River Delta. The most prominent OCPs were dichlorodiphenyltrichloroethane (∑DDT, arithmetic mean=5.11μgkg(-1)), hexachlorocyclohexane (∑HCH, 1.69μgkg(-1)) and ∑endosulfan (10.4μgkg(-1)). The spatial variability of OCPs composition shifted from γ-HCH and o,p'-DDT dominated pesticides in coastal soils to p,p'-DDE dominated pesticides in inland soils. In different land-use types, the percentages of β-HCH and p,p'-DDE are characterized by more recalcitrant components in decreasing order of vegetable fields, cereal fields, cotton fields, wetlands and tidal flats with increasing soil salinity. However, the less recalcitrant components, γ-HCH and o,p'-DDT, showed an opposite trend. Endosulfan sulfate predominated in all land-use types. Residual levels of β-HCH were affected by soil organic matter. The correlations between γ-HCH and clay content and between p,p'-DDE, o,p'-DDT and salinity might associate with the influence of sediment cotransport by the Yellow River and the density of anthropogenic activities in coastal region. Depth distribution of the OCPs in typical soil profiles also implied that local historical usage and sediment transport by the Yellow River both affected the OCPs residual in this region.

Research on Detection and Distribution of Organic Chlorine Content in the Chin-Sha River Basin

This paper collected 18 soil samples in the Chin-sha River basin, and analyzed residues of organochlorine pesticides (OCPs) in soil using gas chromatographic method, revealing the organochlorine pesticide residues, the distribution and sources in the river basin. The results show that, the relatively high sampling residues of organochlorine pesticide distribute in the industrial area. The composition and characteristics of organic chlorine pesticide show that the organochlorine pesticide residues in soil mainly come from the historical use. Compared with the domestic similar research, residual organochlorine pesticides in Chin-sha River basin were lower.

Multiresidue analysis of 30 organochlorine pesticides in milk and milk powder by gel permeation chromatography-solid phase extraction-gas chromatography-tandem mass spectrometry

A method for simultaneous determination of the 30 organochlorine pesticides (OCP) in milk and milk powder samples has been developed. Prior to the gas chromatography-tandem mass spectrometric analysis, the residual OCP in samples were extracted with n-hexane and acetone mixture (1/1, vol/vol) and cleaned up by gel permeation chromatography and solid phase extraction. Selected reaction monitoring mode was used for gas chromatography-tandem mass spectrometric data acquisition to identify and quantify the OCP. To avoid the matrix effects, matrix-matched calibration solutions ranging from 2 to 50 ng/mL were used to record the calibration curve. Limits of quantification of all OCP were 0.8μg/kg. With the exception of endrin, limits of quantification are significantly lower than maximum residue limits set by the European Union and China. The average recoveries were in the range of 70.1 to 114.7% at 3 spiked concentration levels (0.8, 2.0, and 10.0μg/kg) with residual standard deviation lower than 12.9%. The developed method was successfully applied to analyze the OCP in commercial milk products.