摘要
研究了以５－Ｂｒ－ＤＭＰＡＰ分光光度法测定食品中微量锌，对实验条件和共存离子的干扰及掩蔽进行了探讨。在ＯＰ存在下，Ｚｎ（Ⅱ）和５－Ｂｒ－ＤＭＰＡＰ在ｐＨ８．０～１０．０氨性缓冲液中形成有色络合物；λｍａｘ＝５５５ｎｍ，ε＝８．８１×１０４Ｌｍｏｌ－１ｃｍ－１，Ｚｎ在０～５６０μｇ／Ｌ范围内符合比耳定律，变异系数和回收率分别在１．６％～４．６％和９１．１％～１０５％之间。
A spectrophotometric method for the determination of trace Zinc in foods by 5 Br DMPAP has been investigated.The experimental conditions and interferance from coexisting ions were studied.In the presence of OP in alkalescent solution of pH9.0,Zn(Ⅱ) and 5 Br DMPAP formed a coloured complex with an apparent molar absorptivity of 8.81×10 4L·mol -1 ·cm -1 at λmax(=555nm).Beer′s law is obeyed when Zn concentration is in the range of 0～14μg per 25ml.The variation coefficient and recover ratio from this method are within 1.6%～4.6% and 91.1%～105% respectively.
