Method Development in the Determination of Metabolites of Pyrethroids in Urine by Strong Anion Exchange Disk Extraction /In-Vail Derivation and Gas Chromatography-Mass Spectrometry

• Main Authors: Bau-Lain Chen, 陳寶蓮
• Other Authors: Wei-Chao Lin
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/65933829691026522645

碩士 === 國立成功大學 === 環境醫學研究所 === 91 === Pyrethroids have been extensively used as insecticides in agriculture, forestry, horticulture, and residential hygiene. Pyrethroids have been documented as a neurotoxicant as well as a possible genotoxicant in literature. The exposure profile and total body burden of pyrethroids in population draw more and more attention due to their increasing use. The analytical methods developed in the past, however, only targeted on some metabolites instead of full-spectrum application for widely diversified pyrethroids. Moreover, the procedures in previous methods were considerably complicated and time-consuming. The purpose of this study is to establish a more timesaving and simpler analytical method incorporating strong anion exchange (SAX) / in-vail derivatization with gas chromatography/mass spectrometry (GC/MS) in the determination of five urinary pyrethroid biomarkers at the same time. SAX was used in extraction, percolation and enrichment in a single step for the following five urinary pyrethroid metabolites: 3-(2,2-dimethyl)-2,2-dimethyl- (1-cyclopropane)-carboxylic acid (ChCA), cis/trans 3-(2,2-dichlorovinyl)-2,2-dimethyl- (1-cyclopropane)-carboxylic acid (cis/trans Cl2CA), 3-(2,2-dibromorovinyl)-2,2-dimethyl- (1-cyclopropane)-carboxylic acid (Br2CA), 3-phenoxybenzoic acid (3PBA), and 3-(4-hydroxy)-phenoxybenzoic acid (4OHPBA). After nitrogen blow, CH3I was added and in-vial derivatization was achieved following by heating prior to GC/MS determination. We found the method developed in this study reduced the sample preparation time to 2.5 hrs from 4-24 hrs and the chromatographic course to 17 min from 1 hr. The addition of 30μL of NaOH (aq) at 10N to the urine collected from a SD rat after oral exposure to cypermethrin at 3mg was able to effectively improve the recovery rates of biomarkers of interest by possibly breaking down the conjugated forms into free forms as well as eliminate the chromatographic interference. The limits of detection for five pyrethroid metabolites were ranged from 0.32 to 5.52 μg/L. Statistical significance was found in the determination of five pyrethroid metabolites for the urine samples collected from pesticide sprayers (n=22) and from unexposed population (n=20). This method not only can greatly simplify sample preparation procedure but also significantly reduce the consumption of toxic solvents in sample preparation as well as covering more diversified pyrethroids. This method could be more suitable in routine analysis and for screening purpose in the determination of pyrethroid exposure for general population as well as for occupationally exposed groups. Key words: Pyrethroids, biomarkers, SAX, analytical method, solid phase extraction