中药材三七中农药多残留分析的样品前处理方法

Sample pretreatment methods of pesticide residues in Panax notoginseng of Chinese traditional medicine

建立了中药材三七中农药残留分析的两种样品前处理方法, 在样品前处理方法I中, 样品经正己烷与二氯甲烷 （体积比为6：4） 混合溶剂超声提取, 提取液经Envi-carb/NH2 SPE小柱净化; 在样品前处理方法II中, 采用基质固相分散萃取净化法对样品进行提取净化。两种方法所得到的洗脱液, 于旋转蒸发仪上浓缩近干, 二氯甲烷定容后于气相色谱-质谱 （GC-MS） 检测。采用GC-MS的选择离子监测 （SIM） 方式和外标法定量。在优化的样品前处理条件和GC-MS分析条件下, 方法简便、快速, 添加水平为0.01、0.5和2.0 mg·kg-1进行加标回收率实验时, 采用方法I时的回收率为81.90%～102.10%, 相对标准偏差 （RSD） 为3.60%～7.10%; 采用方法II时的回收率为96.26%～104.20%, RSD为3.52%～7.94%; 检出限在0.48～1.34 ng·g-1之间。两种前处理方法的各项技术指标满足农药残留检测要求, 适合三七样品中痕量农药残留的分析。

Two sample pretreatment methods of pesticide residues in Panax notoginseng of Chinese traditional medicine were developed. For Method I, the residues were extracted from homogenized tissue with n-hexane-dichloromethane （6：4） by means of ultrasonication, the crude extract was purified by an Envi-carb/NH2 solid-phase extraction （SPE） column. For Method II, matrix solid-phase dispersion （MSPD） technique was used for extracting and cleaning up. The eluates were concentrated by rotary evaporation, and then were redissolved in dichloromethane prior to GC-MS determination. The determination was performed in selected ion monitoring （SIM） mode with the external calibration for quantitative analysis. Under the optimal conditions, the results indicated that the methods are easier and faster, the recoveries of method I for the spiked standards at concentration of 0.01, 0.5, and 2.0 mg·kg-1 were 81.90%-102.10% with the relative standard deviations （RSDs） of 3.60%-7.10%. The recoveries of method II were 96.26%-104.20% with the RSDs of 3.52%-7.94%. The detection limits （S/N） for residues of pesticides were in the range of 0.48-1.34 ng·g-1. The results indicated that these multiresidue analysis methods can meet the requirements for determination of residue pesticides and can be appropriate for trace analysis of residue pesticides in Panax notoginseng.