LC-ICP-MS测定饮用水中铬形态

Speciation analysis of chromium in drinking water by LC-ICP-MS

目的建立液相色谱—电感耦合等离子体质谱法(LC-ICP-MS)测定饮用水中三价铬和六价铬形态化合物分析方法。方法待测样品与EDTA-2Na络合后,采用Dionex IonPac AG7色谱柱,0.075 mol/L硝酸和0.6 mmol/L乙二胺四乙酸二钠作为流动相进行等度洗脱,液相色谱分离,电感耦合等离子体质谱进行定性和定量分析,在2 min内实现了铬形态分析测定。结果该方法Cr(Ⅲ)和Cr(Ⅵ)的检出限分别为0.2和0.3μg/L,在1.00~80.0μg/L浓度范围内线性良好,相关系数均优于0.999,方法加标回收率为83.7%~115.3%,相对标准偏差均<5%。结论本研究所建立的方法速度快、准确性好、灵敏度高,适用于水源水及饮用水中三价铬和六价铬的定量检测。

Objective To establish an analytical method for determining chromium speciation in drinking water by liquid chromatography-inductively coupled plasma mass spectrometry(LC-ICP-MS). Methods After the sample was complexed with EDTA-2 Na, a Dionex IonPac AS7 chromatographic column was used with a mobile phase of 0.075 mol/L nitric acid and 0.6 mmol/L EDTA-2 Na for isocratic elution, and liquid chromatographic separation was performed. ICP-MS was used for qualitative and quantitative analyses, and chromium speciation was determined within 2 minutes. Results This method had a limit of detection of 0.2 μg/L for Cr(Ⅲ) and 0.3 μg/L for Cr(Ⅵ), and a good linear relationship was observed within the range of 1.00-80.0 μg/L, with a correlation coefficient higher than 0.999. The spike recovery was 83.7%-115.3%, with a relative standard deviation of <5%. Conclusion The method established in this study is rapid, accurate, reliable, and sensitive and can be used for the quantitative determination of chromium speciation in drinking water.