微波消解-原子吸收法测定各类食品中的铜

DETERMINATION OF COPPER IN FOOD BY MICROWAVE DIGESTION-ATOMIC ABSORPTION SPECTROSCOPY

[目的]建立一次消化可同时测定铅、铜等多种金属元素,能有效缩短工作时间,降低劳动强度,提高工作效率,满足检验检疫系统快速、高效、准确的工作要求的方法。[方法]本文通过四因素三水平正交试验,统计分析确定各类食品中铜的最佳微波消解条件,结合原子吸收分光光度法测定食品中的铜。[结果]方法检出低限为0.5mg/Kg;平均回收率为93.5%～106.0%;室内相对标准偏差(RSD)为3.22%～15.2%,室间RSD为2.57%～17.6%;对大米粉和茶叶标准物质分别进行12次测定,铜测定值均在给定值范围内,RSD为3.19%和2.81%;用本法和国标法对奶粉、茶叶、咖啡、可可粉、罐头、糖果等几类样品分别进行平行试验,结果t=-0.577,P=0.574,表明两法的测定结果基本一致。[结论]方法简便快速,准确可靠,重复性及再现性好。

An atomic absorption method with microwave digestion was described for the determination of Copper in various kinds of food. The best condition of microwave digestion was developed combined with atomic absorption spectropbetometric method in each kind of food by orthogonals experiments in four factors and three levels. The limit of detection was 0.5mg/kg, average recoveries were 93.5%～106.0%, the interassay relative standard deviations（RSD） were 3.22%～15.2%,and external laboratory RSDs were 2.57%～17.6%.Standard materials of rice powder and tea were determined 12 times separately, the copper measures were within the given value scope. Carrying on the parallel experiments by this method and the China National Standard method respectively to several kinds of samples, such as powdered milk, tea, coffee, cocoa, canned food, candies and so on, the results were t =-0.577,P = 0.574. It shows that the determinations by two methods are in consistence. This method is simple and fast, accurate and reliable, with good repeatability and the reproducibility.