高效液相色谱–电感耦合等离子体串联质谱法测定水样中6种硒形态

Determination of six selenium speciations in water samples by high performance liquid chromatography inductively coupled plasma tandem mass spectrometry

建立高效液相色谱–电感耦合等离子体质谱法测定水样中硒酸盐、亚硒酸盐、硒代胱氨酸、硒代半胱氨酸、硒代蛋氨酸、硒代乙硫氨酸6种硒形态的检测方法。采用Zorbax SB–Aq反相色谱柱,用pH值分别为2.7、7.0的10 mmol/L柠檬酸溶液(含5 mmol/L己烷磺酸钠)进行梯度洗脱,流量为1.0 mL/min,用电感耦合等离子体串联质谱(加氧模式双四级杆)检测。6种形态硒的质量浓度在1~100 ng/mL范围内与响应强度有良好的线性关系,相关系数均大于0.999,检出限为0.0972~0.1660 ng/mL。测定结果的相对标准偏差为5.65%~7.13%(n=7),样品加标回收率为74.6%~97.5%。该方法快速、灵敏,检出限低,适用于饮用水、河水等水样中硒形态的检测。

A method for the determination of selenate,selenite,selenocystine,methylselenocysteine,selenomethionine,selenoethionine in water samples by high performance liquid chromatography inductively coupled plasma tandem mass spectrometry(HPLC–ICP–MS/MS)was established.A Zorbax SB–Aq reversed-phase chromatographic column was used.The gradient elution was carried out with 10 mmol/L citric acid solution(containing 5 mmol/L sodium hexanesulfonate)with pH of 2.7 and 7.0,respectively,and the flow rate was 1.0 mL/min.The detection was performed by inductively coupled plasma tandem mass spectrometry(double quadrupole in oxygenation mode).There was a good linear relationship between the mass concentration of six selenium speciations and the response intensity in the range of 1–100 ng/mL,the correlation coefficients were all more than 0.999,and the detection limits were 0.0972–0.1660 ng/mL.The relative standard deviations were 5.65%–7.13%(n=7),and the recoveries were 74.6%–97.5%.The method is rapid,sensitive and of low detection limit,which is suitable for the determination of selenium species in drinking water,river water and other water samples.