US EPA

1226495 

Journal Article 

Residue Analysis of Chlorpyrifos and Its Toxic Metabolite TCP in Water by HPLC 

Han, C; Zhu, LS; Wang, J; Wang, JH; Xie, H; Su, J 

2009 

1 

Nongye Huanjing Kexue Xuebao / Journal of Agro-Environment Science
ISSN: 1672-2043 

Journal of Agro-Environment Science 

28 

7 (Jul 2009) 

1552-1556 

A method was developed for analysis the residues of chlorpyrifos and its toxic metabolite 3,5,6-trichloro-2-pyridinol (TCP) in water. In this method, different conditions of mobile phase, different kinds of extraction solvents and different amount of extraction solvents were studied. Ethyl acetate, dichloromethane, chloroform and petroleum ether were tested as the extraction solvent, respectively. And the best extraction was obtained when using ethyl acetate as extraction solvent Water samples were extracted by two step liquid-liquid distribution, 50 mL ethyl acetate was used in the first partitioning step, and 30 mL was used in the second. The detection method was based on using high-performance liquid chromatography (HPLC) with reversed-phase C sub(18) column, and gradient UV detector. The column was maintained at 25 C with a mobile phase flow rate of 1.0 mL; min super(-1). The mobile phase was consisted of methanol-water (90:10, V/V) or acetonitrile-water (90:10, V/V). Chlorpyrifos and TCP were all detected at 300 nm. The retention times of chlorpyrifos and TCP were 6.4 min and 3.6 min when using methanol-water (90:10, V/V) as mobile phase, and 5.6 min and 2.5 min when using acetonitrile-water(90:10, V/V). The detection limits for chlorpyrifos and TCP were found to be 0.5 ng and 0.15 ng, respectively. When adding chlorpyrifos and TCP at the concentration of 0.0165 mg; L super(-1), the average recoveries of chlorpyrifos and TCP from water samples were about 91.4%6105.1% and 90.6%6105.4%, and the relative standard deviation ranged from 0.99%64.12% to 0.29%69.33%. The lowest detectable concentration of chlorpyrifos and TCP in water sample were 2 ng; mL super(-1) and 0.6 ng; mL super(-1). The results showed that the method met the demands of pesticide residue analysis. 

Dichloromethane; Chlorpyrifos; Water Analysis; Water Sampling; Ethyl acetate; Chloroform; Petroleum; Metabolites; Residues; High-performance liquid chromatography; Solvents; Flow rates; Pesticide Residues; Ethers; Standard Deviation; Pesticides; Liquid Chromatography; petroleum ether