气相色谱-质谱法测定苹果中多效唑残留量

苹果样品中的多效唑用丙酬-乙酸乙酯提取，弗罗里硅土柱净化后，用气相色谱-质谱电子轰击源正离子方式进行测定，外标法定量、通过监测离子的相对丰度对阳性结果进行确证。空白苹果样品中添加量在0．02～0．5mg／kg范围时，回收率达到90％～98％，相对标准偏差5．0％～8．6％，检出限为0．02mg／kg。

Determination of Paclobutrazol in Apple with Gas Chromatography - Mass Spectrometry

Paclobutrazol was extracted fromapple samples with acetone/acetic acetate.After solvent evapora-tion,the residue was dissolved in acetone/n-hexane and cleaned up by Florisil column.The elution was con-centrated and the residue was redissolved in n-hexane.The selected ion monitoring mode(ions selected:125,167and236)was used for the measurement of paclobutrazol.When the concentration of paclobutrazol in apple sample was in the range of0.020-0.50mg/kg,the recoveries were90%-98%with relative stan-dard deviations of5.0%-8.6%.There is a good linear correlation(the correlation coefficient was greater than0.999)between the peak areas and concentrations of paclobutrazol between0.05and5.0mg/kg.The limit of detection was0.02mg/kg.