Simultaneous determination of 375 pesticide residues in milk by high performance liquid chromatography-tandem mass spectrometry
A method for the detection of 375 pesticide residues in milk was established by using biphenyl chromatographic column with core-shell technology combined with HPLC-MS/MS.The results showed that the optimum pre-treatment conditions were as follows:the solid and liquid ratio of sample and extraction reagent 1∶2(g∶ml),salt package formula(4 g magnesium sulfate+1 g sodium chloride+1 g sodium citrate+0.5 g disodium hy-drogen citrate),acetonitrile volume 5 ml.The optimal extraction conditions were PhenomenexKinetex Bphenyl column(100×3.0 mm,2.6 μm),and ammonium formate-0.01%formic acid aqueous solution(2 mmol/L)and ammonium formate-0.01%formic acid methanol solution(2 mmol/L)as the mobile phase.Under these optimal conditions,375 pesticide compounds had good linearity in the mass concentration range of 0.5-50 μg/L,and the correlation coefficient R2 was greater than 0.999.The limit of detection(LOD)was 0.5 μg/kg,and the limit of quantification(LOQ)was 1 μg/kg.The average recoveries were 72.89%-110.97%,and the relative standard deviations(RSD)of precision tests results were 1.18%-16.96%.The method was simple,rapid,accurate and reliable,which was suitable for the determination of 375 kinds of pesticide residues in milk.
milkpesticide residueshigh performance liquid chromatography-tandem mass spectrometry