离子色谱法分离弱酸阴离子保留值规律的研究

Study on the Rule of Retention Value in Weak Acid Anion Chromatography

研究了离子色谱弱酸阴离子分析中以氢氧化钠作淋洗液时 ,弱酸阴离子的调整保留时间随淋洗液中氢氧化钠浓度变化的规律 ,建立了二者关系的非线性函数模型。将一元非线性问题转化为多元线性问题求解 ,磷酸根的调整保留值与淋洗液中氢氧化钠浓度关系回归方程的相关系数在 0 99以上。用该数学模型预测磷酸根阴离子的保留值 ,相对误差小于 5 %

In chromatography, if analytes are strong acid anions or strong alkali cations, the dependence of a logarithm of the adjusted retention value on the logarithm of the concentration of the eluent is given by log t R′=const-( j/i )·log C , where j is the charge of the analyte ion, i is the charge of the eluent ion, const is a constant that depends on the column, eluent and analyte ion But in weak acid anion chromatography, existing forms of the sample anion change with the change of the concentration of the eluent So the study on the relationship between retention value of weak acid anion and concentration of the eluent is more difficult Relationship between adjusted retention value of some weak acid anion and concentration of the eluent was studied with sodium hydroxide as eluent The nonlinear fitting function has been set up We transform it into multiple linear fitting to give the answer The correlation coefficients for phosphate defined by the function were over 0 99 The relative errors with the use of function were below 5%