水中多种阴离子离子色谱测定法

Determination of anions in water by ion chromatography

目的建立一种直接进样快速同时测定水中多种阴离子的离子色谱法。方法采用METROSEP A Supp 5 250+METROSEP A Supp 1 Guard组合分离柱,100μl定量环,以Na_2CO_3/NaHCO_3为淋洗液,电导检测,测定水中F^-、ClO_2^-、Cl^-、NO_2^-、ClO_3^-、NO_3^-、SO_4^(2-)等7种阴离子。结果建立的方法,各组分线性范围均达到0~20 mg/L,相关系数r均≥0.999,方法检出限为0.004~0.041 mg/L,浓度相对标准偏差(mRSD)为0.5~2.4%,时间相对标准偏差(tRSD)为0.04~0.90%,37 min内完成测定。结论该方法线性范围宽,相关性良好,精密度和灵敏度高,操作简便,分析速度快,干扰小,适用于生活饮用水和地表水的检测。

[Objective] To establish a direct and quick method for determining the anions in water by ion chromatography.[Methods]By using the combined separating column of METROSEP A Supp 5 250＋ METROSEP A Supp 1 Guard,100 μl loop size,and Na2CO3/NaHCO3 as leacheate,conductivity detection was performed to test the anions of F^-,ClO2^-,Cl^-,NO2^-,ClO3^-,NO3^- and SO4^2- in water.[Results]The method showed good linearity in the range of 0-20 mg/L for each anion,and the correlation efficient（r）were all higher than 0.999. The detection limit was 0.004-0.041 mg/L,concentration relative standard deviation（m RSD）was 0.5%-2.4% and time relative standard deviation（t RSD）was 0.04%-0.90%. The whole detection process was finished within 37 minutes.[Conclusion]The method has the advantages of wide linear range,good correlation,high precision and sensi-tivity,simple operation,fast analysis and little interference,which is applicable for the detection of drinking water and surface water.