氢氧化钡沉淀–碘量法对高锰酸钾和锰酸钾共存时的分别测定

Respective Determination of Potassium Permanganate and Potassium Manganate Coexistence by Barium Hydroxide Precipitation–Iodimetry Method

采用氢氧化钡沉淀– 碘量法对高锰酸钾和锰酸钾共存时的含量分别进行测定.向电解液中加入过量的饱和氢氧化钡溶液,利用锰酸钡和高锰酸钡溶度积的不同进行分离,再用碘量法分别对高锰酸钾和锰酸钾进行测定.结果表明,高锰酸钾和锰酸钾的检出限分别为0.061,0.077 g/L,测定结果的相对标准偏差分别为0.57%和0.72%（n=4）,高锰酸钾的加标回收率为94.12%-95.85%.t 检验结果表明,氢氧化钡沉淀– 碘量法与传统方法对高锰酸钾和锰酸钾的测定结果无显著性差异.该法避免了亚铅酸钠和铬盐的毒性及滴定终点颜色不易判断等缺点,适合于高锰酸钾工业生产中主要成分的快速检测.

The barium hydroxide precipitation–iodimetry method for the determination of potassium permanganateand potassium manganate coexistence was established. By adding an excess of saturated barium hydroxide solution inelectrolyte,they were separated for different solubility of barium manganate and barium permanganate. Then potassiumpermanganate and potassium manganate were determinated respectively by iodimetry method. Results showed that thedetection limits of potassium permanganate and potassium manganate were 0.061,0.077 g/L, and the relative standarddeviation of detection results were 0.57% and 0.72%（n=4）, respectively. The recovery rate of potassium permanganatewas 94.12%–95.85%. t value test results showed that there was no significant difference between the results detected bybarium hydroxide precipitation–iodimetry method and those detected by traditional methods. The method can avoid thedisadvantage of the toxicity of lead acid sodium and chromium salt and the difficulty to judge the color of titration endpoint, it is suitable for rapid detection of the main ingredients for potassium permanganate industrial production.