大米镉检测中消解方法的选择

以标准物质作为参考，选择空白值、精密度、试剂消耗量、消解时间等参数，并从时效性和实验消耗成本上比较分析了检测大米中镉常用的3种消解方法：湿式消解法、干灰化法、微波消解法.实验结果表明：微波消解法试剂消耗量最少，消解时间最短，精密度为2.3％，适合挥发性元素、质控样品检测；干灰化法空白值小于1＆#215;10-5 mg/kg，操作简便，受高温加热的影响相对误差较大，适合大批量样品检测；湿式消解法前期设备投入少，一次性可处理样品18个，但空白值较高，由于方法成熟，为常规实验中最适宜的方法.

Selection of Digestion Method for Detecting Cadmium in Rice

There are several digestion methods for detecting cadmium in rice, like wet digestion, dry ash method, and microwave digestion method. Using rice standard substance, by the blank value, precision, reagent consumption, digestion time comparison parameters, this study attempted to compare these methods in the aspect of timeliness and experiment cost to detect the optimum digestion method. Experiments showed that , microwave digestion reagent consumed the least and enjoyed shortest digestion time, had the precision of 2.3%, which is suitable for the detection of volatile elements, the control samples;dry ashing blank value was less then 1 ＆#215; 10-5 mg/kg, simple operation, high temperature heating effects, resulting in relatively large errors, which is suitable for large-volume sample testing;wet digestion method invovled less pre-equipment investment, which could process 18 samples at the same time, the disadvanage was its higher blank value. Because the method is mature, and of low cost, it is the most appropriate method for routine test.