离子色谱法测定大气降水中低浓度无机阴离子的研究

建立了离子色谱法同时测定大气降水中4种低浓度无机阴离子F^-、Cl^-、SO₄^2-、NO₃^-的方法。以KOH为流动相,使用3.0～30.0mmol/L,1.0mL/min流速进行梯度淋洗。其相关系数均不小于0.999,相对标准偏差0.1%～3%（n=6）,检出限0.003～0.01mg/L（n=9）,加标回收率96.9%～110%,可在22min内完成四组份大气降水样品的测定。

Determination of low concentration inorganic anions in wet precipitation by ion chromatography

A gradient elution run was carried out with KOH as the mobile phase,at a flow rate of 3mmol/L-30.0mmol/L and 1.0mL/min.The mass concentration of the four anions(F^-,Cl^-,SO₄^2-,NO₃^-)had a good linear relationship with the chromatographic height in their respective ranges,the correlation coefficients were not less than 0.999,the relative standard deviation of determination results was 0.1%-3%(n=6),the detection limit of the method was 0.003 mg/L-0.01 mg/L(n=9)and the recoveries of the standard addition were 96.9%-110%.The method is simple,rapid and sensitive,and the whole analysis process is within 22mins.