离子色谱法测定海水中氯离子和硫酸根离子

氯离子和硫酸根离子是海水中重要的无机阴离子，在研究海洋生态变化、海洋循环作用过程与海洋全球气候变化等领域具有重要的指示意义。其测定方法较多，但缺少相应的测试方法。本文对测定海水中Cl^-，SO₄^2-的离子色谱方法进行了优化，选用IonPacAS14碳酸盐选择性离子色谱柱，以3.5 mmol/L Na₂CO₃+1 mmol/L NaHCO₃为流动相，可消除海水样品中碳酸盐及其他阴离子的干扰。该方法对Cl^-检出限为0.29 mg/L，线性相关系数r²=0.999 2，对SO₄^2-检出限为0.42 mg/L，线性相关系数r²=0.997 9。样品的加标回收率在95%~102%，Cl^-和SO₄^2-的相对标准偏差分别为1.92%和4.18%。该方法简便、迅速、灵敏、准确度高，可满足批量海水样品中Cl^-与SO₄^2-的准确测试。

Determination of chloride and sulfate ion in seawater by ion chromatograph

Chloride ions and sulfate ions are important inorganic anions in seawater, and are of great significance for studying changes in marine ecology, processes of ocean circulation and changes in global ocean climate. There are many measurement methods, but the lack of corresponding test methods. In this paper, the ion chromatography method for the determination of Cl^- and SO₄^2- in seawater was optimized. IonPacAS14 carbonate selective ion chromatog­raphic column was selected, with 3.5 mmol/L Na₂CO₃+1 mmol/L NaHCO₃ as the mobile phase, which can eliminate the interference of carbonate and other anions in seawater samples. The detection limit of Cl^- was 0.29 mg/L with good linearity r²=0.999 2, and the detection limit of SO₄^2- was 0.42 mg/L with linearity r²=0.997 9. The recovery of the samples was between 95% and 102%. The relative standard deviations (RSD) of Cl^- and SO₄^2- were 1.92% and 4.18%, respectively. This method is simple, rapid, sensitive, and highly accurate, and it can meet the accurate test of Cl^- and SO₄^2- in batches of seawater samples.