邻菲罗啉法测定低聚异麦芽糖铁Ⅲ配合物铁含量及条件优化

Spectrophotometric iron(Ⅲ)determination and optimizing of isomaltooligosaccharide-iron complex using phenanthroline

建立邻菲罗啉法测定低聚异麦芽糖铁Ⅲ配合物铁含量,并对该方法的试验过程逐一进行条件优化,以确定最佳检测条件。消解因素试验显示酸的种类对消解没有选择性,但随着酸体积分数的增加,加热温度和时间的增大,消解越趋于完全。2mL以上的邻菲罗啉显色剂才能完全络合亚铁离子,且络合物可在pH 3~8条件下放置240 min。铁浓度在1~5mg/L时线性相关性良好,R^2=0.999 9;低聚异麦芽糖铁Ⅲ配合物铁含量分别为42.04%,40.43%,39.45%;平均回收率以及精密度试验结果均显示了该试验方法的精确性。

In this study, the detection approach was established for spectrophotometric determination of iron （ Ⅲ ）, existing in the form of isomahooligosaccharide-iron （ Ⅲ ） complex. The method was opti- mized by operating experiments considering the factors of the process. Several factors effected on isomahooligosaccharide-iron （Ⅲ ） complex digestion, including the volume fraction of acid, the heating temperature and time, and this approach yielded to accurate results except the kinds of acid. The digestion was positively correlated with the acid volume fraction, heating temperature and time. It was found that over 2 mL phenanthroline solution was demanded and that the complexation could maintain stability within pH 3 8 at 240 rain. Good linear correlation personated in 1- 5 mg/L of iron concentra-tion, R2 = 0. 999 9. Iron contents of isomaltooligosaccharide-iron （Ⅲ） complex were 42.04%, 40.43% and 39.45% respectively. Therefore, a simple, rapid, sensitive and selective assay for iron （lid determination was proposed successfully by the results of aver age recovery and precision of the experiments.