采用固相萃取-气相色谱-质谱法测定水果中9种菊酯农药的残留量.水果样品经丙酮-水(5+1)混合液匀质提取,二氯甲烷萃取,石墨碳柱净化.在气相色谱分离中用DB-5毛细管色谱柱为固定相,在质谱分析中采用选择离子监测模式.9种菊酯农药的质量浓度均在0.1~5 mg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.000 6~0.01 mg·kg-1之间.方法用于水果样品的分析,加标回收率在75.0%~106%之间,测定值的相对标准偏差(n=5)在1.6%~4.2%之间.

GC-MS was applied to the determination of residual amounts of 9 pyrethroid pesticides in fruits after separation by solid phase extraction.The fruit sample was extracted homogeneously with acetone-H2O (5+1) mixture,and the extract was further extracted with methylene chloride.The extract obtained was then purified on graphite carbon column.DB-5 capillary chromatographic column was used for GC separation and selected ion monitoring mode was adopted in MS determination.Linear relationships between values of peak area and mass concentration of the 9 pyrethroid pesticides were kept in the same range of 0.1-5 mg·L-1,with detection limits (3S/N) in the range of 0.000 6-0.01 mg·kg-1.The proposed method was applied to the analysis of fruit samples,giving values of recovery and RSD′s (n=5) in the ranges of 75.0%-106% and 1.6%-4.2% respectively.