LC-MS/MS法同时测定4种中草药中155种农药残留

建立了液相色谱-串联质谱(LC-MS/MS)同时测定4种中草药(甘草、银杏叶、菊花和八角茴香)中155种农药残留方法。样品采用乙腈、无水硫酸镁和乙酸钠分散固相萃取(DSPE),再经Cleanert TPH固相萃取(SPE)柱净化,乙腈/甲苯(8:1,V/V)洗脱,液相色谱串联质谱多反应监测模式下测定,外标法定量。实验结果表明,155种农药的检出限(S/N=3)和定量限(S/N=10)范围分别为0.4～34.1μg/kg和1.3～113.7μg/kg;在1.0～2400.0μg/kg浓度范围内,155种农药中有148种农药在4种中草药中线性相关系数平均值R2≥0.9950;在低、中、高3个添加水平,86.5%～97.4%的农药平均回收率在60%～120%范围,94.2%～100.0%的农药相对标准偏差RSD≤20%(n=5)。该方法适用于中草药中农药多残留检测。

Simultaneous determination of 155 pesticide residues in four kinds of Chinese herbal medicines by DSPE-SPE-LC-MS/MS

A method for the determination of 155 pesticide residues in four kinds of Chinese herbal medicines including Radix Glycyrrhizae,Ginkgo biloba,Chrysanthemum,Fructus Anisi Stellati based on LC-MS/MS was developed.DSPE was used in the method,in which the samples were extracted with acetonitrile in the presence of sodium acetate and anhydrous magnesium sulfate.Then the supernatant was transferred to the Cleanert TPH column using acetonitrile/toluene(8:1,V/V) as an eluting solution for purification.The samples were finally determined by LC-MS/MS in multiple reaction monitoring mode(MRM) using the external standard method.Experimental results showed that the LOD(S/N =3) and LOQ(S/N=10) of all pesticides were in the range of 0.4 - 34.1 μg/kg and 1.3 - 113.7 μg/kg,respectively,lower than the MRL drafted by CAC,EU,Japan,United States and other countries and regions.Among 155 targeted pesticides,the average of linear correlation coefficients for 148 pesticides were not less than 0.9950 in the range of 1.0 - 2400.0 μg/kg.The ranges of spiked recoveries at three levels of high,middle and low were from 60% to 120% for 86.5% - 97.4% pesticides,with the relative standard deviations(RSD,n=5) of 94.2% - 100.0% pesticides less than 20%.The established method is simple,and the sensitivity and precision are well enough to meet the requirements for the detection of multiple pesticide residues in Chinese herbal medicine at trace level.