液相色谱-质谱/质谱法检测人参和土壤中多菌灵的残留动态

Residual Decline of Carbendazim in Ginseng and Soil by Liquid Chromatography-Tandem Mass Spectrometry

建立了液相色谱-质谱/质谱法测定50%多菌灵可湿性粉剂在人参和土壤中的消解动态和残留量。多菌灵在0.01-0.5μg/mL质量浓度范围内呈良好线性,相关系数为0.9985,在0.01-0.2 mg/kg加标水平下,多菌灵在人参和土壤中的回收率为82.74%-91.88%,相对标准偏差（RSD）为2.85%-6.28%,最低检出浓度为0.005mg/kg。两年两地残留实验结果表明,拌土施药剂量52 500g a.i./hm^2下,人参和土壤中多菌灵半衰期分别为11.6-13.7d和10.4-13.0d,最终残留量分别在0.0075-0.0332mg/kg和0.0068-0.0428mg/kg之间。建议我国对人参中多菌灵的最大残留限量（MRL）值为0.5mg/kg,最高施药剂量52 500g a.i./hm^2,安全施药间隔期28d。

Liquid chromatography-tandem mass spectrometry（LC-MS/MS）was used to study the residual decline and final residues of carbendazim in ginseng and soil.The method had a good linear correlation（r≥0.9985）in the range of 0.01-0.5μg/mL.The recoveries of carbendazim at spiked level of 0.01-0.2μg/kg were in the range of 82.74%-91.88% with relative standard deviations of 2.85%-6.28%.The minimum detection concentration was 0.005 mg/kg.The results of field trial showed that when the sprayed dose was 52 500 g a.i./hm^2,the half-lives were 11.6-13.7dand 10.4-13.0din ginseng and soil,respectively,and the residues of carbendazim were 0.0075-0.0332mg/kg and 0.0068-0.0428mg/kg.When the most sprayed dosage were 52 500 g a.i./hm^2,the maximum residue limit（MRL）of carbendazim may be suggested to be 0.5mg/kg,and the preharvest interval of carbendazim should be set at 28 d.