Study On Analytical Method Of Chlorinated Organic Pullutants And Preliminary Application

Chlorinated organic pollutants, especially organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), commenced in the middle of19th century for agricultural or industrial purposes, have caused and are still causing harmful effect. Their stability, bioaccumulation and potential toxicity have posesed threat to the environment, food safety and human health. Therefore, improve the determination and surveillance of OCPs and PCBs is helpful to reveal their dynamic and pollution in the environment, which will bring great significance for guaranteeing food safety from the source.In this paper, methods for determination of some common OCPs and several representative PCBs (including indicative PCBs and dioxin-like PCBs) were established. The methods were applied to the detection of OCPs and (or) PCBs in soil, water, vegetable samples and the preliminary research on residue characteristics of19PCBs in soils from a storage site of used capacitors. The results were as follows:1,A method for the determination of17OCPs and7PCBs in soils was developed. The qualitative analysis of target compounds was carried out by GC-ECD with two capillary columns and GC-MS. Samples were extracted using Ultrasonic-wave extraction (UE), and the extraction conditions were optimized. Compared with Soxhlet extraction, UE greatly reducing the time and cost of analysis. Compared with sulfonation and SPE purification, GPC purification can effectively remove the interference.The experimental results showed good linear relationship between the peak area and the concentration (R2=0.9986-0.9999), the average recoveries of OCPs and PCBs ranged from83.2%to105.2%with the RSD (n=5) range from1.08%to6.71%,the limits of detection were between0.010and0.160μg/kg.2,A method for simultaneous determination of16OCPs and8PCBs in water was developed. Samples were extracted with n-hexane by liquid-liquid extraction and purified with Florisil SPE, then condensed by Nitrogen blowing device. The analysis was carried out by using GC-ECD. The experimental results showed good linear relationship between the peak area and the concentration (R2=0.9990-0.9999), the average recoveries of OCPs and PCBs ranged from88.1%to107.0%with the relative standard deviation (RSD, n=5) range from2.87%to10.42%, the limits of detection were between0.001and0.002μg/L3, A method for simultaneous determination of19PCBs in soil and vegetable was developed. At first, PCBs were separated by GC-ECD, but the result was not satisfactory. Then, the qualitative and quantitative analysis of PCBs was carried by GC-MS-SIM, and the chromatography and mass spectrometry conditions were optimized. The experimental results showed good linear relationship between the peak area and the concentration (R2=0.9972-0.9992), the average recoveries of OCPs and PCBs ranged from87.5%to106.8%in vegetables and89.2%to109.5%in soils with the RSD (n=5) range from1.6%to6.7%and2.5%to11.9%respectively, limits of detection were between0.04and0.43μ.g/kg.4,Residue characteristics of19PCBs in soils from a storage site of used capacitors in Yangtze River Delta were investigated. The results of statistical analysis indicated that the concentrations of∑19PCBs in the soils ranged from2.01to5201.20ng/g, with the average concentration of229.38ng/g, which is much higher than general soils but distinctly lower than some storage site soils in China.3-5chlorinated biphenyls in soils accounted for85.43%of∑19PCBs, dominated by tri-PCB28, tetra-PCB52and penta-PCB118. By comparison, PCBs in soils are most Aroclor1242, Aroclor1248and little Aroclor1254. Although the PCBs residues were under control value, we also should pay attention to PCBs pollution in soils at this area, and take further measures to prevent the pollution from expanding.In short, a series of methods established provided the advantages of good selectivity, good reproducibility, high accuracy, low detection limit, and high efficiency, which were suitable for the determination and surveillance of trace OCPs and (or) PCBs in soil, water, vegetable samples.and have reference value.for monitoring and analysis OCPs and (or) PCBs of other samples in food and environmental field.