摘要
本文在已知过量高铁离子存在下,将试样中的植酸转变为植酸铁沉淀,上层清液中未反应的剩余铁离子以2,2’-联吡啶为显色剂,间接光度法测定植酸盐含量作了研究.试验了影响沉淀和显色反应的因素,从而确定了相应的最佳条件.所拟定分析方法的精密度和准确度良好,用于米糠中植酸盐的测定,结果满意.为试样中植酸盐的测定提供了简便、快速、准确的分析方法.同时对米糠中植酸盐的提取进行了初步的探讨.
An indirect spectrophotometric method has been developed to determine phy-tate. The method is based on the precipitate formed between Fe(Ⅲ) and phytate in the acidic medium with known excessive Fe content. The surplus Fe in the upper layer of the solution is determined colorimetrically with 2, 2'-Bipyridine, then the phytate content is calculated. The precipitating conditions of ferric phytate together with the influence of colorimetric condition were examined. Under definite condition the recovery test is favourable. The standard deviation and the coefficient of deviation are 0.16-0.40 and 1.7-5.3% (n = 5) respectively. The method established has been applied to the determination of phytin P in rice bran with satisfactory result.
