溶剂吸收-气相色谱质谱法测定水果中二硫代氨基甲酸盐(酯)类残留量

Residues determination of dithiocarbamate in fruit by solvent absorption-gas chromatography-mass spectrometry

目的建立溶剂吸收-气相色谱质谱法(GC/MS)测定水果中二硫代氨基甲酸盐(酯)类残留量的方法。方法样品经组织捣碎于顶空瓶中,加入SnCl2·HCl溶液,放入水浴中反应2 h后取出冷却,用注射器加入正己烷,振摇萃取后离心取上清液,配制成5.0 mg/L的标准工作液,进行GC/MS检测二硫代氨基甲酸盐(酯)类农药。配制成5.0 mg/L的标准工作液,进行GC/MS检测二硫代氨基甲酸盐(酯)类农药。结果二硫代氨基甲酸盐(酯)类农药的LOD为0.003 mg/kg,LOQ为0.01 mg/kg。平均加标回收率为75.3%~105.1%,相对标准偏差(RSD)为5.9%~8.2%。119份水果样品中,二硫代氨基甲酸(盐)酯类检出16份,均未超标,含量为0.015 mg/kg^0.714 mg/kg。结论该方法灵敏度高,回收率高,检出限低,符合分析要求,适合水果中二硫代氨基甲酸(盐)酯类农药残留检测的要求。

Objective To establish a method for the determination of dithiocarbamate residues in fruit by solvent absorption-gas chromatography-mass spectrometry(GC/MS).Methods The samples were mashed in a headspace vial,added with SnCl2·HCl solution,placed in a water bath for 2 h,then taken out and cooled,added n-hexane with a syringe,shaken and centrifuged to take the supernatant to prepare the standard working solution as 5.0 mg/L,then conducted for the detection of dithiocarbamate residues by GC/MS.Results The LOD and LOQ of dithiocarbamate residues were 0.003 mg/kg and 0.01 mg/kg respectively.The average spiked recoveries were within 75.3%-105.1%,and the relative standard deviation(RSD)was within 5.9%-8.2%.Among the 119 fruit samples,dithiocarbamate residues were detected in16 samples,and the content range was from 0.015 mg/kg to 0.714 mg/kg,which did not exceed the standard.Conclusion The method has high sensitivity,high recovery rate,low detection limit,and could meet the requirement of the detection of dithiocarbamate residues in fruit.