食品中微量硅测定方法的研究

本文采用恒温石墨炉原子吸收技术系统地研究比较了PE普通石墨管、703所热解涂层石墨管、涂锆PE普通石墨管管壁原子化测硅的灵敏度及精度差异;考察了用PE普通石墨管测硅时灰化温度、原子化温度对灵敏度的影响;试验了常用酸和盐,特别是食品中常见的一些共存物质对硅测定的干扰,并对各种食品基体的干扰性质和消除方法进行了研究;试验了氯化铵消除硝酸对石墨管寿命影响的效果。并通过采用较先进的微波消化技术,进而建立了食品中微量硅测定的快速、可靠的分析方法。其样品的最低检出浓度为0.05ug/ml;平均加标回收率为98.1±4.6％;对8种食品中硅进行重复测定,其变异系数均小于8.0％。研究结果表明,本方法能够满足食品中微量硅测定的要求。

Study on the Determination Method of Silicon in Foods

A simple, rapid and quantitative method is presented for the determination of silicon in foods. The sample is digested with HNO3 by microwave sample preparation system, NH4C1 is added in the sample solution in order to eliminate the interference caused by HNO3 on tube life and absorbance are measured by stabilized temperature graphite atomic absorption spectrophotometry with standard tube. The interference caused by sample matrix is eliminated by using standrad addition method. The results showed that sensitivity, precision and accuracy of this method are satisfactory agreement with the re-qurement of food detection. The minimum detectable concentration is 0. 05μg/ml;The recovery is 98. 1±4.6%.