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用过氯酸蒸馏氟,以茜素磺酸钠一次甲基兰作指示剂,硝酸钍滴定氟的方法,是目前广泛使用的测氟方法。尽管氟离子选择电极法正在广泛地推广,而蒸馏测氟法却仍是一种基本的化学分析方法,但是此法尚存在一些问题有待改进,现就此提几点改进意见。一、指示剂的选择最常用的指示剂是茜素磺酸钠一次甲基兰。含氟蒸馏液在PH3.0—3.1的氯乙酸介质中用硝酸钍滴定,溶液由翠绿色变为灰兰色即为终点,但是此法存在着终点难
Distillation of perchlorate with sodium alizarin sulfonate as a methyl blue indicator, thorium nitrate titration fluorine method is currently widely used method of measuring fluoride. Although fluoride ion selective electrode method is widely promoted, and the distillation method is still a basic chemical analysis of fluorine, but this method there are some problems to be improved, to make some comments on this point. First, the indicator of choice The most commonly used indicator is alizarin sulfonate primary methyl blue. Fluorine distillate in pH3.0-3.1 chloroacetic acid medium with thorium nitrate titration, the solution from emerald green to gray blue is the end point, but there is an end point of this method is difficult