Kinds Of Organochlorine Pesticides Research Articles

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.

[Simultaneous determination of 46 semi-volatile organic compounds in water by liquid-liquid extraction-gas chromatography-mass spectrometry].

半挥发性有机物主要包括多环芳烃类(PAHs)、邻苯二甲酸酯类(PAEs)、有机氯农药类(OCPs)和硝基苯类(NBs)等化合物,这些物质多具有致癌、致畸、致突变作用,以及内分泌干扰效应。因此,快速准确测定水中半挥发性有机物非常重要,目前国内尚无水中半挥发性有机物的检测标准。该研究从氮吹温度、水样pH值和萃取时间3个方面进行了优化,旨在建立一种液液萃取-气相色谱-质谱(LLE-GC-MS)同时测定水中46种半挥发性有机物的方法。结果表明:氮吹温度对46种半挥发性有机物的回收率影响不大,考虑回收率及浓缩效率,将氮吹温度设定为35 ℃;水样在中性环境下萃取效果好于碱性环境下的效果;萃取时间由7 min增加至10 min时,回收率也随之提高,但时间增加至15 min时,17种(占比37%)化合物回收率有所增加,29种(占比63%)化合物回收率则呈降低趋势。因此,将萃取时间设定为每次10 min。采用气相色谱-质谱仪进行检测,内标法定量。该方法在20.0~2000 μg/L范围内线性良好,相关系数(r 2)≥0.9916, 46种SVOCs检出限为0.28~16.55 ng/L,定量限为0.92~55.16 ng/L;在0.02、0.2、0.4 μg/L 3个加标水平下的平均回收率为63.6%~125%,相对标准偏差(n=6)为1.03%~17.0%。采用该方法检测了黄河流域济南段的27个地表水样品,检出的物质以PAEs和PAHs为主,2种OCPs在部分点位有检出,NBs均未检出。该方法操作简单,通用性强,准确度及精密度良好,检出限低,适用于地表水及地下水中46种半挥发性有机物的同时检测。

Interaction Effects between Organochlorine Pesticides and Isoflavones In Vitro and In Vivo.

Organochlorine pesticides (OCPs) have caused increasing global concern due to their high toxicity, persistence, bioaccumulation, and significant adverse effects on human health. This study was to explore the interaction effects between OCPs and isoflavones. Six kinds of OCPs and 2 kinds of isoflavones-genistein and daidzein were included to study their effect on MCF-7 cells in vitro. Eighty-one female Sprague-Dawley rats were randomized to 9 groups according to factorial design to study the interaction effect between isoflavones and γ-HCH. Compared to organochlorine pesticides alone group, proliferation rate of MCF-7 cells was lower in 100 μmol/L genistein + organochlorine pesticides and 100 μmol/L daidzein + organochlorine pesticides group (p < 0.05). In vivo study showed that there are interaction effects on kidney weight and liver weight when treated with isoflavones and γ-HCH. The changes in uterine morphology and positive expression of ERα showed inhibition effects between isoflavones and γ-HCH. In conclusion, the data suggests that there are interactions between isoflavones and OCPs in vitro and in vivo.

Gridded inventories of historical usage for selected organochlorine pesticides in Gansu Province, China

HCHs and DDTs were banned in 1983 in China; however, they are still remaining in various environmental media. Since endosulfan was introduced in China in 1994, it is widely used in agriculture. In this study, temporal and spatial uses of endosulfan, HCHs, and DDTs in Gansu province of China have been presented. It is estimated that the total usage is 701 tons for endosulfan between 1994 and 2007, 1,712 tons for HCHs between 1952 and 1983, and 462 tons for DDTs between 1951 and 1983, respectively. Endosulfan usage increased dramatically in 1998 due to its application on other crops except on cotton. The HCH and DDT usage displayed a rapid increase after 1972, reaching the peak in 1976 and in 1975, respectively; since then, they declined until being banned in 1983. The gridded usage inventories of these three kinds of organochlorine pesticides in Gansu province, with a 1/4° longitude by 1/6° latitude resolution, have been created by using different crops for endosulfan and the area of dry farmland for HCHs and DDTs as surrogate data. The most intensive use was in northwestern regions for endosulfan and southeastern regions for HCHs and DDTs in Gansu province.

Determination of organochlorine pesticides in wild shrimps muscle tissue in Lake Taihu and Lake Dongting by Gas Chromatogrphy/Mass Spectrometry

Twenty-nine shrimp samples from 15 sites in Lake Taihu and Lake Dongting were collected and measured, and 8 kinds of organochlorine pesticides (OCPs) in wild shrimps muscle tissue were analyzed with Gas Chromatography/Mass Spectrometry. Hexachlorobenzene(HCB), Chlordane, ∑DDTs(p,p′-DDT、o,p′-DDT、p,p′-DDE、o,p′-DDE、 p,p′-DDD、o,p′-DDD), Aldrin, Dieldrin, Endrin, Heptachlor and Mirex were quantified. The results showed HCB and p,p′-DDE were detected widely in all shrimp samples. HCB residues in shrimp muscle ranged from nd to 13.2μg/kg and p,p′-DDE ranged from 0.790 to 5.82μg/kg. Much higher concentration of OCPs was found in shrimp’s muscle of Lake Taihu than that of Lake Dongting. In addition, the levels of OCPs in shrimps muscle in dry seasons was little higher than in rainy season for two lakes.

Mixed liquids for single-drop microextraction of organochlorine pesticides in vegetables

A new approach for the extraction of nine kinds of organochlorine pesticides (OCPs) from vegetable samples coupling single-drop microextraction with gas chromatography–mass spectrometry was presented. Experimental parameters, such as organic solvent, exposure time, agitation and organic drop volume were controlled and optimized. An effective extraction was achieved by suspending a 1.00 μL mixed drop of p-xylene and acetone (8:2, v/v) to the tip of a microsyringe immersed in a 2 mL donor aqueous solution and stirred at 400 rpm. The approach was applied to the determination of OCPs in vegetable samples with a linearity range of 0.05–20 ng mL −1 for α-, β-, γ-, δ-hexachlorobenzene (BHC) and dicofol, 0.5–20 ng mL −1 for dieldrin and 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (DDD) or 0.5–50 ng mL −1 for 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) and 2-(2-chlorophenyl)-2 (4-chlorophenyl)-1,1,1-trichloroethane ( p, p′-DDT). Correspondingly, the determination limit at an S/N of 3 ranged from 0.05 ng mL −1 for α-, β-, γ-, δ-BHC to 0.2 ng mL −1 for dicofol, dieldrin or p, p′-DDT. The relative recoveries were from 63.3 to 100%, with repeatability ranging from 8.74 to 18.9% (relative standard deviation, R.S.D.). The single-drop microextraction was proved to be a fast and simple approach for the pre-concentration of organochlorine pesticides in vegetable samples.

Studies in the Grazing of Heather Moorland in North-East Scotland. III. Floristics

By the method of SPE-GC/ECD, this paper studied the distribution and composition of organochlorine pesticides (OCPs) in the surface water body of Chaohu Lake. At the 13 sampling sites of study area, a total of 16 kinds of OCPs, including HCHs, DDTs, beta-Endosulfan, Aldrin, hexachlorobenzene, and Heptachlor, were detected. The total OCPs concentration was 0.54-64.01 ng x L(-1), and the main components were HCHs and DDTs, whose average concentrations were 5.56 ng x L(-1) and 16.57 ng x L(-1), respectively, accounting for about 84.75% of the total. The origins of OCPs in study area were historical residues and the recent discharge of pesticides. The concentrations of all existences accorded with the target values of GB 3838-2002. The concentrations of OCPs in the surface water body of Chaohu Lake were much lower, and the risk was low in general.

Studies on the Behavior of Trace Components in Oils and Fats during Processing for Edible Use. I.

Edible oil added with five kinds of organochlorine pesticides and PCB was submitted to deacidification, decolorization and deodorization under a definite laboratory condition, and the amounts of the organochlorine pesticides and PCB in the oil were determined immediately after each process. Results obtained from these experiments are as follows : (1) Concentration of organochlorine pesticides and PCB in the oil remained almost unchanged after deacidification irrespective of the amount of sodium hydroxide used. (2) Dieldrin concentration in the oil decreased markedly by use of activated clay for decolorization, but the concentration of BHC isomers, DDT related substances and PCB hardly decreased. The use of an adsorbent which contains activated carbon gave the result similar to that obtained by the use of activated clay, but the concentration of PCB clearly decreased. (3) The higher the temperature of deodorization treatment, organochlorine pesticides and PCB concentration markedly decreased and deodorization at a temperature usually used in factories would completely remove these chemicals. It was assumed that in this process BHC isomers will be removed from the oil at a lower temperature than DDT related substances. (4) Hydrogenation using nickel catalyst was carried out on some of the oil and this was found to decrease the amount of r-BHC, pp'-DDT and Dieldrin rather than β-BHC and pp'-DDE, but there was almost no decrease in the amount of PCB.