基于QuEChERS法-超高效液相色谱-串联质谱法的5种中药材中35种有机磷农药残留量的快速分析

目的:建立基于QuEChERS结合超高效液相色谱-串联质谱(UPLC-MS/MS)法的三七、川贝母、薏苡仁、桂枝、金银花5种中药材中35种有机磷农药残留量的快速检测方法。方法:采用QuEChERS法对样品进行前处理, Agilent Poroshell C₁₈色谱柱(2.7μm, 4.6 mm×150 mm),柱温35℃,以甲醇-0.1%(v/v)甲酸水溶液为流动相进行梯度洗脱(0~4 min, 20%A; 4~8 min, 20%A → 60%A; 8~12 min, 60%A → 80%A;12~35 min, 80%A → 90%A),流速0.4 mL·min^-1,进样量5μL;采用电喷雾离子源进行正离子模式监测,多反应监测模式(MRM)用于定量分析。结果:35种农药在一定含量范围内线性关系良好,相关系数(R²)均大于0.98。在LOQ、10 LOQ和30 LOQ 3个添加浓度水平进行了添加回收率实验,平均回收率均在70.63%~110.6%之间, RSD在0.66%~14.18%之间。35种有机磷农药成分的定量限在0.12~76.5μg·kg-1之间; 50批药材样品共检出了甲胺磷、倍硫磷及毒死蜱3种农药残留,但均符合标准规定。结论:该方法操作简便快速、经济有效、灵敏可靠,适用于中药材中多种农药残留的快速筛查测定。

Objective:To develop a method for the rapid determination of 35 pesticides in five kinds of Chinese medicinal materials, such as Notoginseng Radix et Rhizoma, Fritillariae Cirrhosae Bulbus, Coicis Semen,innamomi Ramulus and Lonicerae Japonicae Flos by QuEChERS and UPLC-MS/MS. Methods:The samples were prepared by QuEChERS, separated on an Agilent Poroshell C₁₈ column(2.7μm, 4.6 mm×150 mm), by a gradient elution(0-4 min, 20%A; 4-8 min, 20%A → 60%A; 8-12 min, 60%A → 80%A; 12-35 min, 80%A → 90%A)using methanol and 0.1%(v/v)aqueous formic acid as the mobile phase at a flow rate of 0.4 mL·min-1; the injection volume was 5μL. The column temperature was at 35℃. Multiple-reaction monitoring(MRM) scanning was employed for quantification with switching electrospray ion source polarity in positive mode. Results:The results showed that all the 35 pesticides had good linearity in certain ranges with the correlation coefficients(R²) higher than 0.98. The average recoveries of all the 35 organophosphorus pesticides at the three fortification levels(LOQ, 10 LOQ and 30 LOQ)were between 70.63% and 110.6%, with the relative standard deviation between 0.66% and 14.18%. The limits of quantification(LOQs)of 35 organophosphorus pesticids were between 0.12μg·kg-1 and 76.5μg·kg-1. Totally 3 kinds of pesticides, namely, methamidophos, fenthion and chlorpyriphos-ethyl, were detected in 50 lots of samples, and conformed to safety standards. Conclusion:The results demonstrated that the developed method is simple, rapid, economical, sensitive and highly efficient for screening multiple pesticide residues in China medicines.