超高效液相色谱串联质谱法同时测定马铃薯中6种环己烯酮类除草剂

Simultaneous determination of 6 cyclohexanedione herbicides residues in potatoes by ultra-performance liquid chromatography-tandem mass spectrometry

目的建立马铃薯中6种环己烯酮类除草剂残留量的超高效液相色谱-质谱同时检测方法。方法样品经乙腈超声提取,离心后上清液经Envi-carb固相萃取柱净化。采用Dionex C_(18)色谱柱(2.1 mm×100 mm,2.2μm)分离,以乙腈和含0.1%甲酸的5 mmol/L乙酸铵水溶液梯度洗脱,多反应监测模式(MRM)测定,外标法定量。结果 6种环己烯酮类除草剂在2~100μg/L浓度范围内线性关系良好(r≥0.9923),6种环己烯酮类的定量限均为2.0μg/kg,检出限均为0.6μg/kg,6种环己烯酮类除草剂在马铃薯中以2.0、4.0和10.0μg/kg加标时回收率在67.5%~95.8%之间,相对标准偏差均<8.5%。应用该方法对30份马铃薯样品进行检测,共检出阳性样品2份,检出率为6.7%。结论该方法简便、准确,适用于马铃薯中6种环己烯酮类除草剂残留量的同时检测。

Objective To establish a method for analysis of 6 cyclohexanedione herbicides residues in potatoes by ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry（ UPLC-MS/MS）.Methods The target compounds in samples were extracted ultrasonically with acetonitrile.After centrifugation,the supernatant was cleaned up with Envi-carb column.The sample solution was separated on an Dionex C18 column（ 2.1 mm × 100 mm,2.2 μm） with gradient elution using acetonitrile -5 mmol/L ammonium acetate and 0.1% formic acid in water as mobile phase.The identification was performed with tandem mass spectrometer,with electrospray ionization（ ESI） in positive mode under multiple reaction monitoring.The quantification was based on external standard curves.Results The method showed good linearity in the range of 2-100 μg/L（ r ≥ 0.9923）.The limit of quantitation were 2.0 μg/kg.The detection limits of the method were 0.6 μg/kg.The recoveries were within 67.5%-95.8% at the spiked levels of 2.0-10.0 μg/kg,and the relative standard deviations were all less than 8.5%.Six cyclohexanedione herbicides residues were detected in 6.7% of 30 potatoes samples which was determined by the method.Conclusion The method is rapid,specific,accurate,and it is suitable for detection of quinolone and tetracycline residues.