聚乙二醇/无机盐双水相萃取-超高效液相色谱-串联质谱法测定环境水体中5种三嗪类除草剂残留量

UHPLC-MS/MS Determination of Residual Amounts of 5 Triazine Herbicides in Environmental Water with Aqueous Two Phase Extraction Using Polyethylene Glycol and Inorganic Salt

移取10.0mL环境水体样品,加入0.90g聚乙二醇-2000,超声溶解后,加入3.25g硫酸铵,超声萃取10min,离心后移取上层萃取相50μL,用流动相稀释至200μL,经0.22μm有机滤膜过滤,采用超高效液相色谱-串联质谱法测定滤液中5种三嗪类除草剂的残留量。以Zorbax Eclipse XDB-C_(18)色谱柱为固定相,以乙腈(7+3)溶液为流动相,串联质谱分析中采用电喷雾正离子源和选择离子监测模式。5种三嗪类除草剂的质量浓度均在0.100～10.00μg·L^(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)为3.72～24.3ng·L^(-1)。方法用于环境水体样品的分析,加标回收率为80.8%～115%,测定值的相对标准偏差(n=5)为0.17%～6.4%。

The sample(10.0 mL) of environmental water was taken and polyethylene glycol-2000(0.90 g) was added.After ultrasonic dissolution,ammonium sulphate(3.25 g) was added and the mixture was extracted ultrasonically for 10 min.After centrifugation,the upper extraction phase(50μL) was taken and diluted to 200μL with mobile phase.The above solution was filtered with 0.22μm organic filter membrane.UHPLC-MS/MS was applied to the determination of residual amounts of 5 triazine herbicides in the filtrate.Zorbax Eclipse XDB-C18 chromatographic column was used as stationary phase,and acetonitrile(7+3) solution was used as mobile phase.ESI+ and the selected ion monitoring mode were adopted in MS/MS.Linear relationships between values of peak area and mass concentration of the 5 triazine herbicides were kept in the same range of 0.100-10.00μg·L-1,with detection limits(3S/N) in the range of 3.72-24.3 ng·L-1.The proposed method was applied to the analysis of samples of environmental water,giving values of recovery found by standard addition method and RSDs(n=5) of determined values in the ranges of 80.8%-115% and 0.17%-6.4% respectively.