A gas chromatography-tandem mass spectrometric(GC-MS/MS) method was developed for the determination of 5 carbamate pesticides residues,i.e,metolcarb,isoprocarb,fenobucarb,propoxur and pirimicarb in Oolong tea samples.The sample was extracted with hexane-ethyl acetate mixed solution,and the extract was cleaned up with a QuEChERS kit,including 400 mg PSA/400 mg C18/1 200 mg MgSO4.The mixed targets were separated on a Rxi-5 Sil MS(30 m,0.25 mm×0.25 μm) capillary column,and pesticide residues were identified and quantified by GC-MS/MS.5 carbamate pesticides had good linear relationships in each linear range(5-500 μg/kg for metolcarb and propoxur,1-500 μg/kg for isoprocarb,fenobucarb and pirimicarb),and the correlation coefficients were higher than 0.99.The mean recoveries of metolcarb and propoxur in black Oolong tea at spiked levels of 5,20,100 μg/kg were in the range of 77.5%-95.4%,with RSDs(n=6) of 2.1%-6.1%.The LODs and LOQs for the two targets were 1 μg/kg and 5 μg/kg,respectively.The mean recoveries of isoprocarb,fenobucarb and pirimicarb at spiked levels of 1,20,100 μg/kg were in the range of 79.5%-102.5%with RSDs(n=6) of 2.0%-8.2%.The LODs and LOQs were 0.2 μg/kg and 1 μg/kg,respectively.With the advantages of simple operation,high sensitivity and good reproducibility,this method could meet the requirements for the determination of 5 kinds of carbamate pesticides residues in Oolong tea samples.
关键词
乌龙茶QuEChERS氨基甲酸酯农药气相色谱-串联质谱
Keywords
Oolong-teaQuEChERScarbamate pesticidesgas chromatography-tandem mass spectrometry(GC-MS/MS)