导数离子色谱法在水质分析中的应用

Application of Derivative Ion Chromatography in Water Quality Analysis

建立了一种一阶导数离子色谱法测定水样中钙镁离子的方法,该方法在测定前无须对水样进行处理。考察了pH、温度、离子强度等对方法的影响,实验选择在pH为中性、室温下进行。由实验测定得到钙、镁离子的离子色谱图,并对谱图进行一阶求导,分别在钙离子和镁离子一阶离子色谱导数的零交点为6.5 min、7.5 min处读取另一离子的导数值dσ/dt,该数值与钙离子或者镁离子浓度呈现良好的线性关系。采用该方法测定的结果与滴定法测定的结果相一致,表明方法准确、可靠。

A first-order derivative ion chromatography method was established for the determination of calcium and magnesium ions in water samples, compared with previous study, the method requires not pre-treatment of water samples.The effects of pH,temperature and ionic strength on the method were investigated.The experiment was carried out at room temperature in neutral pH.The chromatograms of Ca2+ and Mg2+ were determined under the optimal conditions of ion chromatography.The first-order derivation of the spectrum was carried out, and the derivative value of another ion was read at the zero intersection point of the first order ion derivative of Ca2+ and Mg2+ at 6.5 min and 7.5 min, respectively.The derivative value showed good linearity with the concentration of Ca2+ or Mg2+.The results obtained by the method were consistent with those obtained by titration method, indicating the method to be accurate and reliable.