高效液相色谱-串联质谱法测定青刀豆中毒死蜱代谢物磷酸二乙酯

摘要

建立高效液相-串联质谱法测定青刀豆中的毒死蜱代谢物磷酸二乙酯残留量的检测方法.青刀豆样品经盐酸酸化后用乙腈提取,提取液经活性炭固相萃取小柱净化,以Thermo Scientific Waters SpherisorbRR column-NH2色谱柱为分析柱,乙酸铵水溶液和乙腈体系为流动相,等梯度淋洗.检测器采用三重四极杆串联质谱仪,配备电喷雾电离源,在负离子扫描模式下采用选择反应监测,定量离子为m/z153＞ 125,定性离子为m/z153＞125,79.该方法检测磷酸二乙酯在16μg· L-1到8000μg·L-1范围内有良好的线性关系,方法定量限(S/N=10)为2μg· kg-1,加标回收率为83％～90％,测定值的相对标准偏差小于9.8％.%A high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) method has been developed for determination of chlorpyrifos metabolite di-ethyl phosphate (DEP) in green string bean. The sample was extracted with ethyl acetate/ace-tonitrile(H-l) mixed solvent,purified by carbon SPE column,and then was detected by HPLC -MS/MS. The LC separation was performed on a Thermo Scientific Waters SpherisorbRR col-umn-NH2 with 10 mmol·L-1 ammonium acetate-acetonitrile as the mobile phase. The quantitative and confirmatory determination of the DEP was performed by select reaction monitoring (SRM) mode. The DEP determination revealed good linear relationship over the range from 16μg· L-1 to 8000μg · L-1. The method quantification limits (MQLs) for the analyses was 2μg · kg-1. The recovery was 83%~90% ,with RSD's( n =6) less than 9.8%.