玫瑰红酸钠试纸作外指示剂-氯化钡滴定法测定水中硫酸根  

Determination of sulfate radical in water by barium chloride titration with sodium rhodizonate test paper as external indicator

作　　者：董亦斌[1] 

机构地区：[1]昆明理工大学理学院,云南昆明650093

出　　处：《冶金分析》2013年第4期61-63,共3页Metallurgical Analysis

摘　　要：基于钡与硫酸根沉淀反应后,过量的钡能使玫瑰红酸钠变色,从而建立了玫瑰红酸钠试纸指示、氯化钡滴定测定硫酸根的方法。将滤纸浸入玫瑰红酸钠调配液中,制成的玫瑰红酸钠试纸能作为外指示剂,用于硫酸根的测定。详细探讨和考察了试纸的制作、酸度和共存离子的影响等,结果表明:将滤纸浸入玫瑰红酸钠溶液中,加入醋酸钠溶液进行浸泡,然后在110℃左右于暗处将试纸相互隔开,可急速烘干,干燥后制成的试纸着色性好,稳定性显著提高;在pH 4～6的介质中,试纸显色灵敏,响应快,且大多数常见离子不干扰测定。方法用于水样分析,测定值与重量法测定值相一致,结果的相对标准偏差(RSD,n=7)为0.30%～0.42%。Based on precipitation reaction of barium and sulfate radical, rhodizonic acid disodium salt was discolored by excess barium, the method of determining sulfate radical by barium chloride titra- tion with rhodizonic acid disodium salt test paper as indicator has been established. The filter paper was dipped in rhodizonic acid disodium salt mixing solution, rhodizonic acid disodium salt test paper can be used as the external indicator for the determination of sulfate radical. The effect of test paper production, acidity and coexisting ion influence were discussed and investigated. The result shows that：the filter paper will be dipped in rhodizonic acid disodium salt solution, sodium acetate solution will be joined together to soak , and then test paper will be separated from each other at 110 ℃ or so in the dark, which can be dried rapidly. The dried test paper has better performance in coloring, the stability has been improved notably. In the medium of pH 4-6 ,test paper discolored sensitively and re- sponsed rapidly, the determination will not be interfered by the most common ions. This method was used in the water sample analysis, compared with gravimetric method, the measured value was consist- ent , and the relative standard deviation （RSD, n=7） of the method were between 0. 30 %-0. 42 %.

关 键 词：玫瑰红酸钠 试纸 硫酸根 外指示剂 滴定分析 

分 类 号：X832[环境科学与工程—环境工程] O655.2[理学—分析化学]