The Development Of Organochlorine Pesticides Analytical Methods In Soil And Water

Three analytical methods, including Ordinary Pressure Microwave-assisted Extraction (MAE), Solid Phase disk Extraction and Active Carbon-Calcium Hydroxide-Solid Phase Cartridge Extraction, developed for determination of organochlorine pesticides (OCPs) in soil and water samples. The optimum extraction procedures of the methods were examined by experiment. It provided to the warranties for determining OCPs in environment.The experiment provided the optimum gas chromatography (GC) conditions for OCPs detection, and researched the degradations of Endrin and p, p'-DDT in GC inlet.The OCPs were utilized ordinary pressure MAE to extract, following cleanup by Florisil and detected by GC-ECD. The experiment studied Florisil colum cleanup procedures. The influence of extraction time, solvent, power and temperature were investigated, and found the optimum conditions for ordinary pressure MAE. Soxhlet Extraction(SE), Ultrasonic Extraction (UE) and ordinary pressureMAE methods were compared in soil; the results showed that the recoveries of Endrin and Heptachlorextracted by SE were superior to by ordinary pressure MAE, the percentage recoveries of Heptachlor, Endrin and Aldrin extracted by UE were superior to by ordinary pressure MAE, but percentage recoveries of other OCPs by ordinary pressure MAE were excelled. On spiked soil samples, under the ordinary pressure MAE optimum conditions for 13 kinds of OCPs, the percentage recoveries varied between 84.26% and 105.2%; the standard deviation ranged from 0.009 to 0.853ng/g; the relative standard deviation was from 0.525% to 18.64%; the detection limit of this method ranged from 0.033to 0.853 ng/g.The adsorptive potential of Active Carbon-Calcium hydroxide for solid-phase extraction of OCPs in water was investigated for the first time. The analytes are quantitatively adsorbed on an Active Carbon-Calcium hydroxide -packed cartridge, and then the analytes retained on the cartridge are quantitatively desorbed with suitable amounts of acetone and hexane. Finally, the analytes in the eluent are determined by gas chromatography. Parameters influencing the extraction efficiency, such as volume of the sample solution, pH of the sample, solid-phase extraction adsorbent amount and the eluent solution and eluent volume were examined. Comparative studies showed that Active Carbon-Calcium hydroxide was at least as effective as Liquid-liquid extraction (LLE) for the extraction of OCPs in water. When the extraction volume was less than 300mL there was no OCPs detected for saturation OCPs solution .The accuracy of the proposed method was tested by recovery measurements on spiked samples,...