自动固相萃取-超高效液相色谱串联质谱法测定太湖水和饮用水中9种微囊藻毒素

Simultaneous determination of 9 microcystins in Taihu Lake water and drinking water by automated solid phase extraction coupled with UPLC-MS/MS method

目的建立自动固相萃取-超高效液相色谱串联质谱法测定太湖水和饮用水中9种微囊藻毒素的分析方法。方法水样和藻细胞提取液经HLB固相萃取柱净化浓缩,氮吹挥去溶剂,用甲醇-水(0.04%甲酸)(1∶1,V/V)溶解,0.2μm微孔滤膜过滤,梯度洗脱条件下经BEH C18柱(2.1 mm×100 mm,1.7μm)分离后,采用超高效液相色谱-串联质谱法多离子反应监测(MRM)双电荷模式检测。结果 9种微囊藻毒素的质量浓度为5 ng/ml^200 ng/ml时,线性关系良好,相关系数(r)均>0.998,9种微囊藻毒素的检出限(LOD)为0.074 ng/L^1.65 ng/L,定量限为0.25 ng/L^5.51 ng/L。3种加标水平下的平均回收率为65.3%~102.3%,相对标准偏差(RSD)为1.4%~11.6%。结论该方法前处理效率高、选择性强、灵敏度高,可应用于太湖水和饮用水中9种微囊藻毒素的同时检测。

Objective To develop a method for simultaneous determination of 9 kinds of microcystins in Taihu Lake water and drinking water by automated solid phase extraction coupled with UPLC-MS/MS method. Methods The water samples and the extracts of algal cells were enriched and separated with Oasis HLB. The extract was dried up under a gentle stream of nitrogen.The residue was dissolved with Me OH-H2 O（ 1 ∶1,V/V） containing 0. 04% formic acid. The supernatant was filtered with0. 22 μm membrane. The separation was conducted on a BEH C18 columns（ 2. 1 mm × 100 mm,1. 7 μm）,and detection was performed using tandem mass spectrometry in MRM mode. Results The method had good linearity in the range of 5 ng/ml-200 ng/ml,with correlation coefficients above 0. 998. The detection limits（ LOD） of the method were within 0. 074 ng/L-1. 65 ng/L and the limits of quantification（ LOQ） were within 0. 25 ng/L-5. 51 ng/L. The average recoveries of three spiking levels ranged from 63. 5% to 102. 3%,with the relative standard deviation（ RSD） of 1. 4%-11. 6%. Conclusion This method is efficient,selective and sensitive. It can be applied to the determination of 9 microcystins in Taihu Lake water and drinking water.