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文献用二氯化锡还原黄色的磷钨钒酸为紫红色低价磷钨钒酸,以测定某些钢种及矿石中的钒,但其操作步骤比较繁琐、准确度欠佳。笔者使用硝磷混酸溶样,在加热条件下用高锰酸钾分解碳化物并氧化钒,无需象通常测钒那样用硫磷混酸或高氯酸溶解,经冒烟处理以分解碳化物并氧化钒,可显著提高分析速度。选用硫酸亚铁铵作还原剂,配成溶液可久置不失效,并可提高还原显色速度及显色液稳定性。紫红色低价磷钨钒酸的显色反应灵敏度虽低(ε_(500)=6.5×10~2),
Literature with tin dichloride tin reduction of vanadium tungstosilicate vanadyl low-cost phosphovanadic acid, in order to determine some of the steel and ore vanadium, but the operation steps are more cumbersome, poor accuracy. I use nitric-phosphorus mixed acid to dissolve samples, decompose carbides and oxidize vanadium with potassium permanganate under the heating conditions, do not need to dissolve with phosphoric acid or perchloric acid as usual vanadium, smoke treatment to decompose carbides and oxidize Vanadium, can significantly increase the speed of analysis. Use ammonium ferrous sulfate as reductant, dubbed the solution for a long time without failure, and can improve the reduction of color development and color stability. Although the sensitivity of chromogenic reaction of magenta phosphorothiovanadic acid is low (ε 500 = 6.5 × 10 -2)