两维酸碱-沉淀滴定法同时测定有机酸

Simultaneous Determination of Organic Acids by Two-dimensional Acid-base and Precipitation Titration

本文同时利用难溶有机酸的沉淀反应和酸碱反应，提出了两维酸碱-沉淀滴定法。现有的各种酸碱滴定方法都不能用于酸离解常数十分相近甚至相同的各种酸的同时测定．但当各组分的溶度积有一定的差异时，本文方法可成功地用于这类混合酸的同时测定。主成分回归法用来处理两维滴定体积矩阵。用该法对邻、间、对-氯苯甲酸混合物进行测定，结果良好。同时本文还测定了邻、间、对-氯苯甲酸的固有溶解度和溶度积，并详细讨论了合适的pH测量范围。

Based on the precipitation reaction and acid-base reaction of oranic acids, two-dimensional acid-base and precipitation titration is proposed. The mixture of acids with similar or even same ionization constants can be determined simultaneously by this method, if the solubility products are different. Principal corpponent regression is carried out to determine each component in the mixtures simultaneously. The mixtures of o-, m-, p-chlorobenzoic acid are analyzed and the results are satisfactory. The solubility product and intrinsic solubility of each component is also determined. The suitable pH range for measurement is discussed in detail.