Determination of organophosphorus pesticides using membrane-assisted solvent extraction combined with large volume injection-gas chromatography-mass spectrometric detection.

摘要: Eight organophosphorus pesticides (parathion-methyl, fenitrothion, malathion, fenthion, bromophos, bromophos-ethyl, fenamiphos and ethion) in aqueous samples were analysed by means of membrane-assisted solvent extraction. First a 20 ml extraction vial was filled with 15 sample. Then the membrane bag consisting nonporous polypropylene put into 800 microl organic solvent. The analytes separated from layer transporting them through material small amount technique fully automated successfully combinable large volume GC-MS. To achieve an optimum performance several conditions investigated. Cyclohexane chosen as acceptor phase. impact salt, methanol, pH value, well working parameters like stirring rate agitator time, studied. Moreover, influence matrix effects examined adding different concentrations humic acid sodium salt. Detection limits ng/l level achieved using injection injecting 100 microl. recovery values ranged 47 to 100% relative standard deviation for three measurements between 4 12% (except bromophos-ethyl: 22%). linear dynamic range 0.001 70 microg/l. applicability method real tested spiking eight red wine, white wine apple juice samples.