A sensitive and selective liquid chromatography-positive mode electrospray ionization-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of indoxacarb residue in 21 plant-derived foods,such as maize,peanut,walnut,soybean oil,green tea,grape,leek,mushroom and Chinese prickly ashy.The analyte in plant oil sample was extracted with n-hexane and acetonitrile,and the analyte in other kinds of samples was extracted by acetonitrile.Different types of samples were cleaned up by various methods.The extracts of grain,oil crops,nut and plant oil were cleaned up by gel permeation chromatography(GPC),the extract of tea was purified with solid phase extraction(SPE) column,the extracts of fruits,vegetables,edible fungus and spice were cleaned up with dispersive solid-phase extraction(dSPE) sorbents,namely primary secondary amine(PSA),octadecylsilane(C18) and graphitized carbon black(GCB).Then indoxacarb in the extract was separated on a reversed phase C18 column using an isocratic elution program of 0.1% formic acid-acetonitrile(30∶70).Qualitative analysis was performed by electrospray ionization in positive mode(ESI+) under multiple reaction monitoring(MRM) mode.The matrix-matched calibrations were used to quantify the residue concentrations.The calibration curves showed good linearities in the certain concentration range for different matrices,with correlation coefficients(r2) more than 0.993.The average recoveries of indoxacarb in different matrices were in the range of 73.7%-115.2% at three spiked concentration levels,and relative standard deviations(RSD,n=5) were not more than 13.1%.The limits of quantitation(LOQ) were 1.5-9.5 μg/kg in different matrices.The method is versatile,sensitive and accurate,and could meet the detection requirements of indoxacarb residue in plant-derived foods.
关键词
茚虫威液相色谱-串联质谱法植物源性食品
Keywords
indoxacarbliquid chromatography tandem mass spectrometry(LC-MS/MS)plant derived foods
Study of Indoxacarb Residue Degradation in Tea and Tea Infusion by Ultra High Performance Liquid Chromatography Coupled with Tandem Mass Spectrometry after Dispersive Solid Phase Extraction Cleanup
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