花草茶中11种杀菌剂QuEChERS-超高效液相色谱-串联质谱快速测定法

目的同时建立检测花草茶中11种杀菌剂的超高效液相色谱串联三重四极杆质谱(UPLC-MS/MS)测定法。方法粉碎均匀的花草茶样品经Qu EChERS试剂萃取,DisQuE净化,采用含有0.5%甲酸及乙腈为流动相进行梯度洗脱,经UPLC CORTES C18色谱柱(1.6μm,2.1×100 mm)分离,正离子模式,检测模式应用多反应监测(MRM),采用基质液配制标准系列,外标法定量。结果标准曲线范围为1.0～100.0 ng/ml时,11种杀菌剂检测得到了线性关系良好的回归方程,相关系数(r2)>0.990,检出限为0.10～1.00μg/kg,定量限为0.30～3.00μg/kg。测定回收率的样品3个添加水平分别为10、20、50μg/kg,得到78.39%～95.06%之间的回收率,1.8%～7.2%的相对标准偏差(RSD)。结论 QuEChERS-UPLC-MS/MS测定法能满足同时检测花草茶中11种杀菌剂残留的测定要求,具有操作简便、经济、快速的优点,同时具有良好的重现性、准确度和灵敏度。

Rapid determination of 11 fungicides in herbal tea by QuEChERS and ultra-high performance liquid chromatography-tandem mass spectrometry

[Objective] To establish a method for the determination of 11 fungicides in herbal tea by QuEChERS and ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).[Methods]The samples were soaked with water and extracted with acetonitrile,then were extracted by QuEChERS and were purified by DisQuE. The analytes were separated on a UPLC CORTES C18 column(1.6 μm,2.1×100 mm) through a gradient elution using aqueous formic acid and acetonitrile as mobile phases. Positive electrospray ionization was used. Qualitative work was performed using select dynamic multiple reaction monitoring(MRM) mode. Quantization was performed using external standard method considering matrix effects.[Results]The correlation coefficients(r^2) were greater than 0.990,which indicated that the linear dependence of the 11 fungicides were good in the range of 1.0-100.0 ng/ml. The limit of detection and limit of quantitation of all the 11 fungicides were 0.10-1.00 μg/kg and0.30-3.00 μg g/kg,respectively. with the sample addition level of 10,20 and 50 μg/kg,the recoveries were in the range of 78.39%-95.06% and the relative standard deviations(RSD) ranged from 1.8% to 7.2%.[Conclusion]QuEChERS-UPLC-MS/MS method has the advantages of rapidity,simple operation,economy,good reproducility,accuracy and sensitivity for the detection of the 11 fungicides residues in herbal tea.