盐酸氯丙嗪、盐酸丙嗪及盐酸异丙嗪与1,2萘醌-4-磺酸钠在50%的硫酸溶液反应生成红色,分别在530、515及515毫微米处有最大吸收,可用于这类药物及其制剂的含量测定。方法:精密称取相当于75毫克吩噻嗪类(盐酸盐)药物的片剂粉末,移入100毫升容量瓶中,加约75毫升蒸溜水及1滴稀硫酸,振摇10分钟,以蒸溜水稀释至刻度,混匀,放置5分钟。然后,以干滤纸过滤,初滤液10毫升弃去,再吸取滤液10毫升以蒸溜水稀释 Chlorpromazine hydrochloride, promethazine hydrochloride and promethazine hydrochloride reacted with sodium 1,2-naphthoquinone-4-sulfonate in 50% sulfuric acid solution to produce red color with maximum absorption at 530, 515 and 515 nm, respectively, Determination of the content of such drugs and their preparations. Methods: Weigh accurately the equivalent of 75 mg of phenothiazine (hydrochloride) tablet powder, transferred to a 100 ml volumetric flask, add about 75 ml of distilled water and a drop of dilute sulfuric acid, shaken for 10 minutes to steam Dilute the water to the mark, mix well and leave for 5 minutes. Then, dry filter paper filter, the initial filtrate was discarded 10 ml, and then draw the filtrate 10 ml diluted with distilled water