重量法测定铝酸钠溶液中总硫和低价硫含量

Determination of total sulfur and low valence sulfur content in sodium aluminate solution by gravimetric method

提出了采用重量法测定铝酸钠溶液中总硫量和低价硫合量的方法，其中一份铝酸钠溶液加过氧化氢氧化低价硫测定总硫量，另一份铝酸钠溶液直接加盐酸溶液使低价硫分解而测定其中硫酸盐中的硫，总硫量减去硫酸盐中的硫即为低价硫合量。优化的测定条件为：盐酸用量为30mL；过氧化氢用量为5mL；氯化钡溶液用量为20mL；陈化时间2h；灼烧时间50min。不同浓度的样品加标回收率为97．9％-100．7％之间，相对标准偏差（n=6）分别在0．24％～0．81％之间。方法简单，准确度和精密度高，可以满足生产控制分析需求。

A method for the determination of total sulfur and low valence sulfur in sodium aluminate solution by gravimetric was proposed, the low valence sulfur in one of sodium aluminate solution was oxidized by hydrogen peroxide in order to determine the total sulfur, and the sulfur was determined in the sulfate by adding the hydrochloric acid solution to decompose the low valence sulfur in another sodium aluminate solution, the low valence sulfur was obtained by subtracting the sulfur in the sulfate form the total sulfur. Conditions of determination were optimized and given as follow： amount of hydrochloric acid： 30mL; amount of hydrogen peroxide： 5mL; amount of barium chloride solution： 20mL; aging time： 2h; burning time： 50min. The recoveries of standard samples addition were in the range of 97.9% - 100.7% , and values of RSD （ n = 6 ） were in the range of 0.24% - 0.81%. It was a simple method suitable for the demand of production control analysis with high accuracy and precision.