超高效液相色谱-串联质谱法测定人参中磺酰脲类除草剂残留量

建立了人参中15种磺酰脲类除草剂残留量的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法。样品中残留的农药经乙腈提取、石墨化炭黑(ENVI-Carbon)固相萃取柱净化后,使用含1%(v/v)甲酸的甲醇-二氯甲烷(20:80, v/v)洗脱,UPLC分离,最后采用电喷雾串联质谱在正离子多反应监测(MRM)扫描模式下进行测定。15种农药在2～100 μg/L的质量浓度范围内线性关系良好,相关系数在0.996和0.999之间。对人参中15种农药在5、25和50 μg/kg 3个添加水平下的回收率进行了测定,其平均回收率在84.9%和104.3%之间,相对标准偏差在2.4%和11.9%之间。各种农药的定量限均为5 μg/kg。该方法操作简便,净化效果好,灵敏度、准确度和精密度均符合多残留检测技术的要求,可为中药材中磺酰脲类除草剂污染状况调查提供检测方法支持。

Simultaneous determination of sulfonylurea herbicides in ginseng by ultra performance liquid chromatography-tandem mass spectrometry

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of the fifteen sulfonylurea herbicides in ginseng. The pesticides were extracted with acetonitrile, cleaned-up by an ENVI-Carbon solid phase extraction cartridge, eluted with 1% formic acid in methanol-dichlormethane (20:80, v/v), separated with UPLC and detected with MS/MS in multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI+). The method was validated at three fortification levels in ginseng. The validation results were as follows. The standard calibration curves for the fifteen sulfonylurea herbicides all showed linear over the range of 2~100 μg/L with the correlation coefficients between 0.996 and 0.999. The average recoveries of the fifteen sulfonylurea herbicides at the three fortification levels of 5, 25 and 50 μg/kg were between 84.9% and 104.3% with the relative standard deviations (RSDs) between 2.4% and 11.9%. The limit of quantification (LOQ) was defined as the lowest concentration that could be measured with acceptable precision and accuracy. The LOQs of all the fifteen sulfonylurea herbicides in ginseng were 5 μg/kg. It was indicated that this method is easier, more sensitive and has a better purification effect. The sensitivity, accuracy and precision of the method were all acceptable. So, this method can be further applied to investigating the contamination status of traditional Chinese medicine by the sulfonylurea herbicides