硝酸铵氧化—亚铁滴定法测定氮化锰硅合金中锰

Determination of Manganese in Nitrided Manganese Silicon Alloy by Ammonium Nitrate Oxidation-Ferrous Titration

试样于硝酸、氯氟酸、磷酸混合溶液溶解后，在磷酸冒微烟时，用硝酸铵将锰定量地氧化成紫红色的三价锰。在硫磷混酸介质中，以N-苯代邻氨基苯甲酸为指示剂，用硫酸亚铁铵标准滴定溶液还原三价锰至二价锰，根据硫酸亚铁铵标准滴定溶液消耗用量计算锰的百分含量。分析结果满意。

The sample was dissolved within phosphoric-nitric-hydrofluoric mixed solution, when the phosphate was smoking in micro scale, manganese was quantitatively oxidized into purple trivalent manganese. In the phosphoric acid medium, taking N-phenyl anthranilic acid as an indicator, the standard ti- tration solution of ferrous ammonium sulfate was used to reduce trivalent manganese to bivalent manga- nese, then, the percent content of manganese was calculated according to the consumption of ferrous ammonium sulfate standard titration solution, and the analysis result was satisfying.