Spectrophotometric determination of ampicillin sodium in the presence of its degradation and polymerization products
Spectrophotometric determination of ampicillin sodium in the presence of its degradation and polymerization products
复制标题
分光光度法测定氨苄青霉素钠的降解产物和聚合产物
DOI：
10.1111/j.2042-7158.1974.tb09302.x
复制
发表时间：
1974
影响因子：
3.3
通讯作者：
H. Bundgaard
中科院分区：
文献类型：
--
作者：
H. Bundgaard
建立了氨苄西林钠[6-（d（-）-苯乙酰氨基）青霉烷酸钠盐]的分光光度测定方法。该方法包括在pH 9的水溶液中用乙酸酐乙酰化氨苄青霉素，生成α-乙酰氨基苄基青霉素，然后在325 nm处测量α-乙酰氨基苄基青霉烯酸硫醇汞，在pH 6·8的1·0 m咪唑和8倍10− 4 m氯化汞溶液中于60°加热30 min后定量生成。已证明降解产物不会干扰方法，而含有完整β-内酰胺环的氨苄西林的二聚和聚合产物能够与咪唑反应形成青霉烯酸。已经开发了一种涉及在氨苄青霉素仅轻微降解的条件下酸催化打开这些产物的β-内酰胺环的技术，除了允许选择性测定氨苄青霉素外，该技术还允许测定聚合物。
A spectrophotometric method is described for the quantitative determination of ampicillin sodium [sodium salt of 6‐(d(–)‐phenylacetamido) penicillanic acid]. The method involves acetylation of ampicillin with acetic anhydride in aqueous solution at pH 9 to yield α‐acetamido benzylpenicillin and subsequent measurement at 325 nm of α‐acetamidobenzylpenicillenic acid mercuric mercaptide, formed in a quantitative yield on heating for 30 min at 60° in a 1·0m imidazole and 8 times 10−4m mercuric chloride solution at pH 6·8. It has been demonstrated that degradation products do not interfere in the method whereas those di‐ and polymerization products of ampicillin which contain an intact β‐lactam ring are capable of reacting with imidazole with the formation of penicillenic acid. A technique involving acid‐catalysed opening of the β‐lactam ring of these products under conditions where ampicillin is degraded to only a minor extent has been developed, and besides permitting a selective determination of ampicillin the technique permits the determination of the polymeric substances.