三种饮用水中主要阳离子的离子色谱法检测及其分布特征

Determination by Ion Chromatography and Distribution Characteristics of Main Cations in Three Drinking Waters

通过建立的离子色谱-抑制电导法检测天然饮用矿泉水、管网末梢水和地表水水样中主要阳离子(Li+、Na+、NH+4、K+、Mg2+、Ca2+、Sr2+)的浓度,并分析不同类型饮用水中阳离子的浓度水平差异及分布特征。采用IonPac CS16(5 mm×250 mm)分离柱和IonPac CG16(5 mm×50 mm)保护柱,在40℃的柱温下,以30 mmol/L甲基磺酸(MSA)为流动相,流速为1.0 mL/min。结果表明,NH+4在饮用天然矿泉水和管网末梢水水样中均未被检出,地表水中的检出浓度≤1.89 mg/L,Li+和Sr2+的检出浓度普遍较低(Li+≤0.026 mg/L,Sr2+≤0.263 mg/L),检出浓度最高的是Na+和Ca2+。不同类型水样中阳离子检出浓度平均值顺序均为:地表水>管网末梢水>饮用天然矿泉水。

The concentration of main cations(Li+,Na+,NH+4,K+,Mg2+,Ca2+,Sr2+)in drinking natural mineral water,tap water and surface water samples was measured by ion chromatography(IC)with suppressed conductivity detection. And the concentration levels and distribution characteristics of the cations were discussed. The separation of cations was performed on the separation column IonPac CS 16(5 mm×250 mm)and guard column IonPac CG16(5 mm×50 mm)with 30 mmol/L methane sulfonic acid(MSA)as eluent delivered with flow rate 1.0 mL/min. The column temperature was set as 40 ℃. The results showed that NH+4 was not detected both in drinking natural mineral water and tap water,but it was found(≤1.89 mg/L)in surface water. The detection concentration of Li+(≤0.026 mg/L)and Sr2+(≤0.263 mg/L)were generally lower in all samples. The average concentration of 7 kinds cations in water samples showed the following order:Surface water>tap water>drinking natural mineral water.