原子吸收测定酸雨钾,钠,钙,镁干扰因素探讨及其消除

Study on Interferences in Simultaneous Determination of K、Na、Ca、Mg in Acid rain by Atomic Absorption Spectrometry

主要讨论了用原子吸收分光光度法测定酸雨K、Na、Ca、Mg中主要阴离子AC-、NO3-、CIO4-、C1-、SO42-、PO43-F-对测定的干扰和采用硝酸锶做为干扰抑制剂的最佳使用浓度。结果表明:AC-<10.0mg/L、CIO4-<10.0mg/L、C1-<15.0mg/L、F-<10.0mg/L对K、Na、Ca、Mg测定无干扰;酸雨中含有大于0.50mg/L的PO34-、NO3-就可降低钙的吸光度,但含量达10.0mg/L也不影响K、Na、Mg的测定;含有大于0.50mg/L的SO24-对钙镁的测定都有抑制作用,且随着干扰物浓度的提高吸光值有变小的趋势,选择0.5%硝酸锶可消除以上干扰。

In this paper, tile simultaneous determination of K ,Na, Ca ,Mg by atomic absorption spectrometry in tile presence of some anions AC^- ,NO3^- ,CIO4^- ,Cl^- ,SO4^2- ,PO4^3- ,F^- in acid rain was studied. The interference of these main anions were investigated and the optimum concentration of inhibitor Sr（ NO3 ） 2 was proposed. Tile results were shown that 10. 0mgAC^- . 10.0mg/LClO4^- . 15.0mg/L Cl^- , 10.0mg/L F^- have no interference to determination of K, Na, Ca, Mg; Acid rain containing more than 0.50mg/L PO4^3- or NO; can reduce Ca^2＋ absorbency, but the content of 10.0mg/L PO4^3- or NO3^- have no interference on determination of K,Na,Mg. The SO4^2- Containing more than 0.05 mg/L will restrain the absorbency of Ca^2＋ ,Mg^2＋ ,and along with the enhancement of interference concentration the absorbency will small change in the trend . In our experiment, 0.5% Sr（ NO3 ）2 was chosen to avoid the interference from these anions and the results were satisfaction.