分散固相萃取-超高效液相色谱-串联质谱法检测大豆中6种典型农药残留

本研究建立了分散固相萃取-超高效液相色谱-串联质谱法同时检测大豆中灭草松、三氟羧草醚、氯虫苯甲酰胺、甲氨基阿维菌素苯甲酸盐、吡唑醚菌酯、精喹禾灵及其代谢物喹禾灵酸的多残留分析方法,为监测大豆生产中的农药应用风险提供方法。该方法具有简单、快捷、准确、灵敏度高的特点。样品经1%甲酸-乙腈振荡提取后,分散固相萃取净化,流动相为甲酸铵-水溶液(含0.01% 甲酸)和甲酸铵-甲醇溶液(含0.01% 甲酸),采用苯基色谱柱进行分离,基质匹配标准曲线外标法定量分析。结果表明:目标农药及代谢物在0.001~1 mg/kg添加水平下平均回收率为78.1%~116.0%,相对标准偏差(RSD)为1.6%~20.5%,该方法在0.001~1 mg/kg范围内线性良好(R2≥0.991 1),定量限(LOQ)可达0.001 mg/kg。基于此方法对内蒙古产区的大豆样品进行测定,发现大豆中灭草松、氯虫苯甲酰胺、吡唑醚菌酯有检出,残留量在<0.001~0.024 mg/kg之间,喹禾灵酸、三氟羧草醚、甲氨基阿维菌素苯甲酸盐残留量均<0.002 mg/kg。采集的大豆样品中6种目标农药残留量均符合我国农药最大残留限量标准安全要求。

Determination of six typical pesticide residues in soybean by dispersive solid-phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

An analytical method for the simultaneous detecting bentazone, acifluorfen, chlorantraniliprole, emamectin benzoate, pyraclostrobin, quizalofop-P-ethyl and its metabolite quizalofop-acid in soybean by ultra-performance liquid chromatography-tandem mass spectrometry was established, which provided an effective tool for monitoring the residue risk of pesticides in soybean. The method was simple, fast, accurate and sensitive. The sample was extracted by 1% formic acid-acetonitrile and purified by dispersive solid phase extraction. The mobile phase was ammonium formate-water solution (containing 0.01% formic acid) and ammonium formate-methanol solution (containing 0.01% formic acid). Phenyl chromatographic column was used for separation, and matrix matching standard curve external standard method was used for quantitative analysis. The results showed that the average recoveries of the target compounds and their metabolites at the spiked levels of 0.001-1 mg/kg ranged from 78.1% to 116.0%, with the relative standard deviations (RSD) ranged from 1.6% to 20.5%. The linear relationships were good in the range of 0.001-1 mg/kg (R2≥0.991 1), and the limits of quantification (LOQs) were 0.001 mg/kg. Furthermore, soybean samples collected from Inner Mongolia were determined by this method. It was found that bentazone, chlorantraniliprole, and pyraclostrobin were detected in soybean, ranging from <0.001 mg/kg to 0.024 mg/kg. The residues of quizalofop-acid, acifluorfen and emamectin benzoate were all lower than 0.002 mg/kg. The six target pesticide residues in soybean samples all meet the safety requirements of the maximum residue limit of pesticides in China.