依米丁的比色测定法——次氯酸钠法

依米丁的含量測定,文献記載有容量法、重量法、非水溶液滴定法、螢光分析法、比色法等。药典一般采用容量法,卽以有机溶媒提取生物碱后,再用酸碱滴定的方法。但依米丁在加热或遇光时极易变貭而成去氫依米丁(dehydroemetine),往往影响結果的准确性。为了避免加热,有的药典用过量的酸来提取醚层中的生物碱,然后用碱滴定剩余的酸。关于比色法,Allport等建議用过氧化氫法;Rojahn等报告用苦味酸

THE SODIUM HYPOCHLORITE METHOD FOR THE COLORIMETRIC DETERMINATION OF EMETINE

Ten ml of a solution of emetine hydrochloride in 1:1 diluted hydrochloric acid (containing up to 0.1 mg of anhydrous salt per ml), warmed to 40℃, was treated with 0.20ml sodium hypochlorite solution (containing about 2.6—2.8 mg Cl₂ per 100 ml), and the orange-yellow colour developed was measured within 10—25 minutes interval in a colorimeter using a 460 mμ filter. The colour intensity was found to obey Beer's law. The method was found to give results in close agreement with the official method adopted in Chinese Pharmacopoeia 1953.