日人田村文造等于六十年代后期报道了吸收度比值法。据称这种分析方法可用于一些在水溶液中滴定终点不明显或者不能滴定的弱酸、弱碱及其盐类物质,如有机酸碱金属盐类等。此法已在日本药局方第9版中的氨基比林等5种药物的含量测定中采用。我们试用此法于医院的一些制剂分析,较为满意,现介绍如下。基本概念吸收度比值法是将分光光度法用于中和滴定,以解决某些突跃不明显,难以确定终点的物质。测定时如等当点消耗的标准溶液量为Vml,实际加入的量为 V’ml,则可有 X=V/V’,X 即为中和度的倒数(X=1为等当点;X>1为等当点前;X<1为等当点后)。再选用一种适当的酸碱指示剂,其 PKa 值要在该中和反应的等当点 pH 附近,并且其酸式色和碱 Japanese Tamura Manchu equal to the late sixties reported absorbance ratio method. It is said that this method can be used for some weak acids, weak bases and their salts, such as organic acid alkali metal salts, which titrate the aqueous solution without obvious or titration. This method has been used in the Japanese Pharmacopoeia 9th edition of aminopyrine and other drugs used in the determination of five. We try this method in the hospital for some preparation analysis, more satisfied, are presented below. The basic concept of absorption ratio method is to use spectrophotometry and titration in order to solve some of the sudden jump is not obvious, it is difficult to determine the end of the material. Determination of the standard solution such as consumption equivalent points when the amount of Vml, the actual amount of added V’ml, you can have X = V / V ’, X is the reciprocal of the degree of neutralization (X = 1 for the equivalent point; X> 1 is before the equivalence point; X <1 after the equivalence point). A suitable acid-base indicator is then chosen which has a pKa value around the pH point of the neutralization reaction and its acid color and base