| Summary: | 碩士 === 國立中興大學 === 化學系 === 93 === A novel sample pretreatment method combining hollow fiber protected liquid phase microextraction in-situ derivatization is developed. The determination of synthetic pyrethroids metabolites in environmental water and urine include cis-, and trans-3 -(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-, and trans-Cl2CA), cis-3-(2,2 -dibromovinyl)-2,2-dimethylcyclopropane -1-carboxylic acid (cis-Br2CA), 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA), and 3-phenoxybenzoic acid (3-PBA). 2-phenoxybenzoic acid (2-PBA) served as internal standard. The sampling apparatus is assembled by a microsyringe pre-filled with derivatization agent, 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and diisopropylcarbodiimide (DIC), and then inserted 2-cm polypropylene hollow fiber into the needle. Before sampling the hollow fiber was soaked and filled with 1-octanol. After adjusted the sample pH to 1.0 and immersed the sampling hollow fiber into the aqueous solution (5 mL, 70℃ water bath and stirred with 1250 rpm). The metabolites are diffused through the hollow fiber and collected in 1-octanol for 10 mins. After extraction of these chemicals, separation and detection were carried out using capillary gas chromatography with electron capture detector. The limit of detection for all analytes was 0.56 and 1.65 ng/mL in water and urine. The inear range was obtained in the concentration of between 0.004-1 μg/mL with correlation coefficients between 0.9734 and 0.9998. This pretreatment technique of pyrethroid metabolites, compared with liquid liquid extraction after derivatization. The new method used the organic solvent no more than microliter and shorten one fourths of analysis time. It would apply on the urinary of 22 pesticides workers who produce these pesticides. To analysis pyrethroid metabolites in urine, collecting in 24 hour, evaluate expose risk of the workers in pesticides factory.
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