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自从1935年卡尔·费希尔开始用滴定法测定各类物质中的水份以来,滴定法有了更多的应用。通常,所用试剂为碘的甲醇溶液,二氧化硫,有机碱“RN”。后者是作为缓冲液所使用的。滴定过程中,试样所含水的反应如下所示: I_2+SO_2+3RN+CH_3OH+H_2O→2RN·HI+RN·HSO_4CH_3 滴定终点一般采用电化学方法来确定。例如使两电极间保持恒定的电流,来测定其间相应的电压。当溶液中——出现痕量的碘,则电压急剧下降,于是,指示出了滴定终点。卡尔·费希尔方法是一种非常有用的分析工具。但是,在检测滴定度和随后的滴定
Titration has been used more since Karl Fischer began titrimetric determination of water in various substances in 1935. In general, the reagents used are iodine in methanol, sulfur dioxide, organic base “RN”. The latter is used as a buffer. During the titration, the reaction of the water contained in the sample is as follows: I_2 + SO_2 + 3RN + CH_3OH + H_2O → 2RN · HI + RN · HSO_4CH_3 Titration end point is generally determined by electrochemical method. For example, to maintain a constant current between the two electrodes to measure the corresponding voltage therebetween. When a trace amount of iodine is present in the solution, the voltage drops sharply, thus indicating the end of the titration. The Karl Fischer method is a very useful analytical tool. However, the titer is checked and the subsequent titration