离子色谱法同时测定水中六种阳离子

SIMULTANEOUS ION CHROMATOGRAPHIC DETERMINATION OF SIX CATIONS IN WATER

研究了用抑制电导离子色谱法一次进样同时测定水中Li+ 、Na+ 、NH+ 4、K+ 、Mg2 + 、Ca2 +的色谱法条件 ,相对标准偏差小于 0 .5 % ,加标回收率在 97.5 %～ 10 4 .0 %。在水质分析中运用t检验法 ,比较了用钙、镁离子浓度计算和传统方法测定的总硬度之间是否存在显著性差异。

It is reported that Li +? Na +? NH + 4? K +? Mg 2+ ? Ca 2+ are determined simultaneously by ion chromatography(IC). The optimum chromatographic conditions are studied thoroughly. RSD′s found are less than 0 5%. Recoveries tested by the standand addition method are in the range of 97.5%～104.0%. Ten IC determinations of water hardness with the CRM issued by the State Research Center For CRM′ (90.0mg·L -1 , expressed as CaCO 3) was done and the data obtained are treated statistically by the t test. It is found that not significant error is found between the average results and the certified value. The detection limits for Ca 2+ and Mg 2+ by IC method achieved to a value of 0.05mg·L -1 which is much lower than the detection limit of the EDTA titration method. More accurate results can be obtained by the IC method.