title: Analysis of bacteria degradation products of methyl parathion by liquid chromatography/electrospray time-of-flight mass spectrometry and gas chromatography/mass spectrometry.
abstract: The biodegradation of the organophosphorus insecticide methyl parathion (MP) in aqueous environment by bacteria isolated from river sediment has been studied. Two species of bacteria which show strong MP degradation ability are identified as Shewanella and Vibrio parahaemolyticus. The biodegradation of MP proceeded rapidly with the formation of a series of intermediate products, which were analyzed using a combination of GC/MS and HPLC/ESI-TOFMS techniques. The major products tentatively identified include a series of reduced products of MP. Results demonstrate that the coupling of TOFMS to HPLC enhances further the capability of LC-MS in the identification of polar organic species in complex environmental samples. Degradation pathways leading to the formation of these products are proposed which involves first the reduction of nitro to amino group in MP, followed by combination with some intrinsic matters of bacteria. The mechanism and products from biodegradation are quite different from those of photocatalytic process for which the main intermediates included methyl paraoxon and 4-nitrophenol.
authors.affiliation: Department of Chemistry and The Key Laboratory of Analytical Science of MOE, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Zheng
authors.forename: Xiaoru
authors.initials: X
authors.lastname: Wang
authors.forename: Frank S C
authors.initials: FS
authors.lastname: Lee
mesh_terms: D001711:Biotransformation; D002853:Chromatography, Liquid / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D053858:Metabolic Networks and Pathways; D008743:Methyl Parathion / Q000032:analysis / Q000378:metabolism*; D020592:Shewanella / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014736:Vibrio parahaemolyticus / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D008743:Methyl Parathion