流动注射-化学发光法测定湖水中的As(Ⅲ)

Flow-injection chemiluminescent determination of As(Ⅲ) in lake water

基于As（ III）在碱性介质中对Luminol -KMnO4体系化学发光抑制作用，建立一种测定湖水中As （ III）的新方法。工作中，对泵速、光电倍增管高压、Luminol和KMnO4的浓度等实验参数进行了优化。结果表明，在优化条件下，1×10-4～1．2×10-2 mg/L的As（III）对Luminol-KMnO4发光的减弱有良好的线性关系（R2＝0．9970），检出限为8．2×10-5mg/L，相对标准偏差（RSD）（n＝11，c ＝5×10-3mg/L）为0．5％.该方法具有简便、快速、准确、重现性好等特点，可用于湖水中As（III）的测定，结果令人满意。

A new method for the determination of arsenic ion in water based on the decreasing effect of arsenic ion on Luminol-KMnO4 chemiluminescence system in alkaline solution has been developed by flow -injection chemiluminescence method . The detecting parameters, such as flow rate, high voltage of PMT, concentration of Luminol and KMnO4, were optimized.Un-der the optimum conditions , the emission intensity is proportional to the concentration of arsenic ion in the range of 1 ×10 -4 ~1.2 ×10-2 mg/L.The detection limit for arsenic ion （S/N=3） turned out to be 8.2 ×10 -5 mg/L, and the relative standard deviation for 11 determinations using a 5 ×10 -3 mg/L arsenic ion containing solution is 0.5%.The method is simple, rapid, accurate and good reproducibility .The proposed method has been successfully applied to the determination of arsenic ion in re -al samples with satisfactory results .