OP乳化剂存在下对羧基偶氮羧光度法测定中药中的微量钙  

Spectrophotometric Determination of Microamounts of Calcium in Chinese Herbal Medicine with p-carboxycarboxylazo in the Presence of Emulsifier OP

作　　者：陈玉英[1] 杜迎翔[1] 罗国安[1] 李勇[1] 

机构地区：[1]中国药科大学分析化学教研室,南京210009

出　　处：《分析测试学报》1993年第1期71-74,共4页Journal of Instrumental Analysis

摘　　要：研究了表面活性剂OP乳化剂存在下对羧基偶氮羧光度法测定钙的条件及其应用。在柠檬酸介质中,加入OP乳化剂大大加快了钙与试剂的显色反应速度,提高了络合物的稳定性和选择性。测定条件下,络合物最大吸收波长为718 nm(△λ=157 nm),表观摩尔吸光系数ε=1.52×10~5L·mol^(-1)·cm^(-1)。用标准加入回扣法测定钙,0～0.4μg/mL符合朗伯-比耳定律。用于测定山茱萸、山药、黄芪中的钙,回收率在97.52～102.0%之间,变异系数小于1.0%。The colour reaction of calcium with p-Carboxycarboxylazo in the presence of emulsifierOP and its analytical application have been studied. In citric acid medium, the reaction rate isaccelerated and the stability and selectivity of the complex are improved by the addition ofemulsifier OP. Under these conditions calcium reacts with p-carboxycarboxylazo to form asensitive and stable β-type complex, having an absorption maximum at 718 nm(Δλ=157nm) withan apparent molar absorptivity of 1.52×10~5 L·mol^(-1). cm^(-1). The complex formation is completewithin 8 min in a small volume and the resulting complex is stable for at least 10 h after dilu-tion. The detect range is 0～10μg of calcium in 25 mL solution by using a standard addition-deduction method. The microamounts of calcium in Fructus Corni, Rhizoma Dioscoreae and Ra-dix Astragali has heen determined. The precision and recovery are both satisfactory.

关 键 词：对羧基偶氮羧 分光光度法 中药 钙 

分 类 号：R284.1[医药卫生—中药学]