title: Determination of the 1'S and 1'R diastereomers of metolachlor and S-metolachlor in water by chiral liquid chromatography-mass spectrometry/mass spectrometry (LC/MS/MS).
abstract: An enantioselective method for the separation and quantification of the diastereomer pairs of metolachlor and S-metolachlor in surface and ground waters is presented. Samples are purified and concentrated using a C18 (octadecyl silica) solid-phase extraction (SPE) procedure and analyzed by chiral column liquid chromatography-mass spectrometry/mass spectrometry (LC/MS/MS) interfaced with either atmospheric pressure chemical ionization (APcI) or atmospheric pressure photoionization (APPI) sources. The overall mean percent procedural recoveries (percent relative standard deviations) are 89% (10.6%) for surface water and 80% (9.1%) for ground water. The method limit of quantitation (LOQ) is 0.10 ppb. The method validation was conducted under U.S. EPA FIFRA Good Laboratory Practice Guidelines 40 CFR 160.
authors.affiliation: Environmental Fate Department, Syngenta Crop Protection, Inc., Post Office Box 18300, Greensboro, North Carolina 27419, USA. kent.kabler@syngenta.com
authors.forename: A Kent
authors.initials: AK
authors.lastname: Kabler
authors.forename: Sunmao
authors.initials: S
authors.lastname: Chen
mesh_terms: D000081:Acetamides / Q000032:analysis* / Q000737:chemistry*; D000390:Air Ionization; D001274:Atmospheric Pressure; D002851:Chromatography, High Pressure Liquid; D007477:Ions / Q000737:chemistry; D013058:Mass Spectrometry; D010777:Photochemistry; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry*
chemical_list: D000081:Acetamides; D007477:Ions; D014867:Water; C051786:metolachlor