Fe(Ⅲ)显色分光光度法测定δ-ALA的研究

The Study of Determing δ ALA with Spectrophotometry of Fe(Ⅲ) Colorating

δ－ＡＬＡ与乙酰乙酸乙酯在ｐＨ值５．８时发生缩合反应，生成吡咯衍生物．此衍生物在强酸介质中与Ｆｅ（Ⅲ）生成橙红色物质，以分光光度法进行测定，最大吸收峰为４８０ｎｍ，ε为６．６×１０３Ｌ（ｍｏｌｃｍ）－１，线性范围为０～４００ｍｇ／０．０２５Ｌ，检测限为０．５ｇ／０．０２５Ｌ．考察了部分共存物质的干扰．该方法已应用于δ－ＡＬＡ合成中成品及半成品的分析，结果令人满意．

A new method of determining δ ALA was described in this paper. At pH=5.8, δ ALA interacts with ethy lace loacetale to produce pyrrale derivative. The derivative can combin with Fe(Ⅲ) and from a orange red colour material in strong acid medium. The material was determined by spectrophotometry. Its manium absorption peak is 480nm, ε is 6.6×10 3 L(mol·cm) -1 , linear range is 0～400mg/0.025 L, and detect limit is 0.05g/0.025 L. Some interferential substances were studied. The method was applied for the analysis of finished and half finished product of δ ALA, with satisfactory results.