本文介绍复方新诺明片不经分离,直接用比色法测定甲氧苄氨嘧啶及磺胺甲基异(口恶)唑含量的方法。甲氧苄氨嘧啶的测定,是使其与溴酚兰形成离子对,在418nm 处测定吸收度;磺胺甲基异(口恶)唑的测定,是在不除去甲氧苄氨嘧啶情况下,使与 N-1-萘乙二胺二盐酸盐试剂显色,于545nm 处测定其吸收度。方法:1.标准液的配制:分别精密称取大约20mg 甲氧苄氨嘧啶及磺胺甲基异(口恶)唑溶于2ml 甲 This article describes the compound cotrimoxazole tablets without separation, direct colorimetric determination of trimethoprim and sulfamethoxazole (oxazole) content of the method. Trimethoprim determination, is to make it with bromophenol blue ion pair, measured at 418nm absorbance; sulfamethoxazole (oxazole) determination, is not removed in the case of trimethoprim, The reagent was developed with N-1-naphthylethylenediamine dihydrochloride and its absorbance was measured at 545 nm. Methods: 1. Preparation of standard solution: respectively weighed about 20mg trimethoprim and sulfamethoxazole (oxazole) dissolved in 2ml A