液相色谱串联质谱法测定土壤中环己烯酮类除草剂及其代谢物残留量

Determination of residues of cyclohexenone herbicides and their metabolites in soil by liquid chromatography tandem mass spectrometry

[目的]建立超声波辅助萃取-超高效液相色谱-串联质谱法测定土壤中8种环己烯酮类除草剂及2种代谢物的分析测试方法。[方法]土壤样品经二氯甲烷超声波提取,氨基化的多壁碳纳米材料净化,溶剂转化后经C_(18)色谱柱分离,以5 mmol/L甲酸铵水溶液和甲醇作为流动相进行梯度洗脱,多反应监测(MRM)正离子模式(ESI+)电离扫描,基质匹配标准曲线外标法定量。[结果]8种环己烯酮类除草剂及2种代谢物的线性关系良好,相关系数均大于0.999,方法检出限为0.01~0.1μg/kg,定量限为0.03~0.3μg/kg,在高、中、低3个空白样品添加水平下,8种环己烯酮类除草剂及2种代谢物的平均回收率在71.81%~111.04%之间,相对标准偏差为0.46%~10.30%。[结论]该方法操作简便、快速、准确,适用于土壤中环己烯酮类除草剂及其代谢物的残留检测。

[Aims]A method was established for the analysis and testing of 8 cyclohexenone herbicides and2 metabolites in soil using ultrasonic assisted extraction and ultra-high performance liquid chromatography tandem mass spectrometry.[Methods]The soil samples were extracted by dichloromethane assisted with ultrasound,purified by aminated multi walled carbon nanomaterials,and separated by C_(18)chromatography column after solvent conversion,using 5 mmol/L ammonium formate aqueous solution and methanol as mobile phases for gradient elution,with multiple reaction monitoring(MRM)positive ion mode(ESI+)ionization scanning.Quantification was performed using a matrix matching standard curve external standard method.[Results]There was a good linear relationship between 8 cyclohexenone herbicides and 2 metabolites,with correlation coefficients greater than 0.999.The detection limit of the method was 0.01-0.1μg/kg,with a quantification limit of 0.03-0.3μg/kg.At the addition levels of high,medium and low blank samples,the average recovery rates of 8 cyclohexenone herbicides and2 metabolites ranged from 71.81%to 111.04%,with a relative standard deviation(RSD)of 0.46%to 10.30%(n=6).[Conclusions]This method is fast,accurate and easy to operate,which is suitable for residual detection of cyclohexenone herbicides and their metabolites in soil.