食品中微量钒测定方法的研究

本文采用恒温石墨炉原子吸收技术系统地研究比较了普通石墨管、热解涂层石墨管、涂锆热解涂层石墨管测钒的灵敏度差异;考察了热解涂层石墨管测钒时灰化温度,原子化温度及“冷却步骤”(“Cooling down”技术)的使用对灵敏度的影响;试验了常用酸和食品中主要共存物质对钒测定的干扰并初步探讨了硝酸的干扰机理和干扰的消除方法;试验比较了各种样品处理方法,并对微波消化技术进行了详细的实验研究;建立了测定食品中微量钒快速、准确、可靠的分析方法。其样品的最低检出浓度为0.02ppm;平均加标回收率为98.2±6.1％;标准参考样品NBS-SHM1566中钒的测定结果为2.22+0.08ppm(其标定值为2.3+0.1ppm)。

Study on the Determination of Vanadium in Foods

A simple, rapid and quantitative method is presented for the determination of vanadium in foods. The sample is digested with HNO3 by microwave samplepreparation system,NH3·H2O is added in the sample solution in order to remove the interference caused by HNO3, and absorbance are measured by stabilized temperature graphite furnace atomic absorption spectrophotometry with calcium matrix modifier and pyrolytically coated tubles. The results showed that sensitivity, precision and accuracy of this method are satisfactory agreement with the requirement of food detection. The minimum detectable concentration is 0.02ppm; The recovery is 98.2±6.1%. The results for vanadium determination in NB5-SRM 1566 is 2.22±0.08ppm (certified value is.2.3±0.1 ppm).