title: Multiresidue screen for organophosphorus insecticides using gel permeation chromatography--silica gel cleanup.
abstract: A multiresidue screen for quantitative determination of 43 organophosphorus insecticides in 5 g of plant and animal tissues is described. The organophosphorus insecticides are extracted with methanol-dichloromethane (10 + 90, v/v) and cleaned up using automated gel permeation chromatography with hexane-ethyl acetate (60 + 40) eluant and in-line silica gel minicolumns. Concentrated extracts are analyzed by gas chromatography with flame photometric detection. The method recovers 43 organophosphorus insecticides in the range of 72 to 115%. Analysis of fortified bovine liver (n = 5) shows an average 95.9 +/- 4.8% recovery at the 0.05 micrograms/g level and 93 +/- 3.8% at the 0.5 micrograms/g level. Analysis of fortified bovine rumen content (n = 5) shows an average 98 +/- 4.2% recovery at the 0.1 micrograms/g level and 98.7 +/- 2.8% at the 1 micrograms/g level. Method detection limits ranged from 0.01 to 0.05 micrograms/g for the compounds studied using a nominal 5 gram sample.
authors.affiliation: University of California, California Veterinary Diagnostic Laboratory System, Davis 95616.
authors.forename: D M
authors.initials: DM
authors.lastname: Holstege
authors.forename: D L
authors.initials: DL
authors.lastname: Scharberg
authors.forename: E R
authors.initials: ER
authors.lastname: Richardson
authors.forename: G
authors.initials: G
authors.lastname: Möller
mesh_terms: D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D005766:Gastrointestinal Contents / Q000737:chemistry*; D005782:Gels; D007306:Insecticides / Q000032:analysis*; D008099:Liver / Q000737:chemistry*; D009943:Organophosphorus Compounds; D010573:Pesticide Residues / Q000032:analysis*; D012015:Reference Standards; D015203:Reproducibility of Results; D012822:Silicon Dioxide
chemical_list: D005782:Gels; D007306:Insecticides; D009943:Organophosphorus Compounds; D010573:Pesticide Residues; D012822:Silicon Dioxide