超高效液相色谱串联质谱法测定上海青基质中吡虫啉和嘧霉胺残留

Determination of Imidacloprid Residues and Pyrimethanil Residues in Green Vegetable(Brassica rapa var. chinensis) by Ultra Performance

本文研究建立了超高效液相色谱-四级杆串联质谱(UPLC-MS/MS)同时检测上海青基质中吡虫啉和嘧霉胺残留量的方法。上海青样品经乙腈提取,SPE氨基固相萃取柱净化(乙腈+甲苯(3+1)洗脱)后,以乙腈-0.1%甲酸溶液为流动相进行超高效液相色谱梯度洗脱分离,质谱多反应监测模式检测,以保留时间和子离子比定性,外标法定量。结果表明,吡虫啉和嘧霉胺的方法定量限(LOQ)分别为3.1×10-6 mg/kg和3.6×10-7 mg/kg,在0.0005~0.5 mg/L线性范围内,两种农药的相关系数为0.9995以上。添加水平在0.02~0.2mg/kg范围内,吡虫啉和嘧霉胺平均回收率分别为99.1%~105.8%和99.1%~110.0%之间,相对标准偏差(RSD)分别小于1.23%和1.64%。该方法操作简单、线性范围宽、灵敏度高、稳定可靠,可满足当前国内外蔬菜中此类药物残留量的检测要求。

A method for simultaneous determination of imidacloprid residues and pyrimethanil residues in green vegetable（Brassica rapa var. chinensis） by using Ultra performance liquid Chromatography-Tandem Mass Spectrometry（UPLC/MS/MS） was established in this paper. The green vegetable（Brassica rapa var. chinensis） samples were extracted by acetonitrile and purified by an amino solid phase extraction（SPE） column（eluted by acetonitrile ＋ toluene（3＋1））, and then the gradient elution was applied in ultra performance liquid chromatography separation by using the acetonitrile-0.1% formic acid solution as mobile phase. Samples were detected by mass spectrometry multi reaction monitoring model, using retention time and sub-ion ratio as qualitative analysis and the external standard method as quantitative analysis. Tandem mass spectrometry with electrospray ionization and multiple reaction monitoring interface in an external standard manner. The results showed that the limits of quantitation（LOQ） of imidacloprid and pyrimethanil were 3.1×10-6 mg/kg and 3.6×10-7 mg/kg respectively, and the correlation coefficients of two pesticides were more than 0.9995 in the linear range of 0.0005~0.5 mg/L. In addition, the average recoveries were 99.1%~105.8% for imidacloprid and 99.1%~110.0% for pyrimethanil in the range of 0.02~0.2 mg/kg, and the relative standard deviations（RSD） were less than 1.23% and 1.64%, respectively. The proposed method had the advantages of simple operation, wide linear range, high sensitivity and reliabilty, which met the requirements for the detection of such drug residues in vegetables at home and abroad.