混合弱酸溶液中各种弱酸的相对电位滴定法测定  

Determination of Weak Acids in Mixture by Relative Potentiometric Titration

作　　者：邢宝忠[1] 张永琴[1] 刘荫藩[1] 余翼鹰 

机构地区：[1]天津大学化学系,天津300072

出　　处：《分析化学》1996年第8期961-963,共3页Chinese Journal of Analytical Chemistry

摘　　要：本文提出一种测定混合弱酸中各种弱酸的相对滴定法。在滴定过程中，当溶液达到一定的pH值时，滴定剂的耗量应与混合物中各弱酸的含量有关，其定量关系可表示为V＝K0＋K1αHA1＋K2αHA2。据此可以求出混合酸中各种弱酸的含量，本法具有较高的准确度和精密度，甚至当待测酸的PKa值差约为1时，亦能获得满意结果。A relative titration method for determining weak acids in mixture is developed.This method is based on the fact that during the titration the amount of titrant consumed to reach a fixed value of pH is relative to the contents of weak acids in the mixture. The quantitative relation expresses as V = K0 +KlαHA1 +K2αHA2. The contents of the acids in mixture can be determined separately by this method. The results of measurements show high accuracy and precision even when the difference of pKa values is Only about 1.

关 键 词：相对滴定 弱酸混合物 电位滴定 弱酸 

分 类 号：O623.611[理学—有机化学] O657.15[理学—化学]