气相色谱-质谱法测定黑木耳中草甘膦和氨甲基膦酸残留量

Determination of glyphosate and aminomethylphosphonic acid residue in Auricularia auricula by gas chromatography-mass spectrometry

中文关键词:  衍生化  气相色谱-质谱法  草甘膦  氨甲基膦酸  干制黑木耳

英文关键词:derivatization  gas chromatography-mass spectrometry  glyphosate  aminomethylphosphonic acid  dried Auricularia auricula

中文摘要:

      目的 建立气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)测定黑木耳中草甘膦及其主要代谢物氨甲基膦酸残留(aminomethylphosphonic acid, AMPA)的分析方法。方法 干制黑木耳样品经二氯甲烷脱色、水提取、盐酸沉淀蛋白、乙醇沉淀多糖后, 与三氟乙酸酐和七氟丁醇进行衍生化反应, 经气相色谱柱分离后, 在选择离子监测(selected ions monitoring, SIM)模式下进行草甘膦和氨甲基膦酸含量的测定, 外标法定量。结果 干制黑木耳中草甘膦在0.001~0.050 μg/mL范围内呈现良好线性(相关系数r2=0.9993), 检出限为0.02 mg/kg, 定量限为0.04 mg/kg, 在0.04、0.08、0.20 mg/kg 3个添加水平下, 平均回收率为82.4%~93.4%, 相对标准偏差为7.8%~9.5% (n=6); 氨甲基膦酸在0.0005~0.0500 μg/mL范围内呈现良好线性(相关系数r2=0.9996), 检出限为0.01 mg/kg, 定量限为0.02 mg/kg, 在0.02、0.08、0.20 mg/kg 3个添加水平下, 平均回收率为85.6%~96.8%, 相对标准偏差为5.7%~9.3% (n=6)。结论 该方法针对干制黑木耳基质, 样品前处理过程简单, 净化除杂效果好且回收率高, 满足农药残留分析实验室对黑木耳中草甘膦和氨甲基膦酸残留的检测要求。

英文摘要:

      Objective To establish a method for the determination of glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) in Auricularia auricular by gas chromatography-mass spectrometry (GC-MS). Methods Dried Auricularia auricula samples were decolorized by dichloromethane, extracted by water, precipitated by hydrochloric acid, precipitated by ethanol, and then derivatized with trifluoroacetic anhydride and sevoflubutanol, separated by gas chromatographic column, selected ions monitoring was performed, the content of glyphosate and AMPA were determined in SIM mode and quantified by external standard method. Results In dried Auricularia auricula, glyphosate showed a good linearity in the range of 0.001?0.050 μg/mL (correlation coefficient r2=0.9993), the limit of detection and the limit of quantification of glyphosate were 0.02 and 0.04 mg/kg, respectively, the average recoveries were 82.4%?93.4% with the relative standard deviations of 7.8%?9.5% at the 3 supplemental levels of 0.04, 0.08 and 0.20 mg/kg (n=6); AMPA showed a good linearity in the range of 0.0005?0.0500 μg/mL (correlation coefficient r2=0.9996), the LOD and LOQ of AMPA were 0.01 and 0.02 mg/kg, respectively, the average recoveries were 85.6%?96.8% and the RSDs were 5.7%?9.3% (n=6) at the 3 supplemental levels of 0.02, 0.08 and 0.20 mg/kg (n=6). Conclusion For dried Auricularia auricula, the sample pretreatment process of this method is simple, its purification effect is favorable and their recoveries are proper, which meets the requirements of pesticide residue analysis laboratory for the residue detection of glyphosate and APMA in Auricularia auricula.