不同消解方法测定饲料中铅、镉、铜、铬、镍含量的研究

Determination of lead,cadmium,copper,chromium and nickel in feed by different digestion methods

试验旨在推荐更适用于可同时检测饲料中多元素的方法。通过对比分析干灰化法、微波消解法、湿法消解法、石墨消解法的优缺点,研究不同消解方法测定饲料中铅、镉、铜、铬、镍含量的影响。结果显示,4种消解方法均具有较低检出限,方法回收率86%~96%,相对标准偏差(RSD)为0.53%~6.13%,线性关系良好,标准物质测定结果均在标准值不确定范围内,均可用于饲料中多元素的检测。采用石墨消解法测定结果显著优于其他方法 (P<0.05),湿法消解法较干灰化法、微波消解法的铬、铜、镉测定值显著偏高(P<0.05)。研究表明,石墨消解法集消解赶酸一体化,可按照设定程序自动完成消解全过程,消解时间固定,工作效率高,便于高通量样品分析,设备以及耗材成本与其他3种方法相比具有很大优势。

The experiment was to recommend a method more suitable for simultaneous detection of multiple elements in feed. By comparing and analyzing the advantages and disadvantages of dry ash method, microwave digestion method, wet digestion method and graphite digestion method, studied the different digestion methods on the content determination of lead, cadmium, copper, chromium and nickel in feed. The results showed that the four digestion methods had low detection limits, the recovery rate was 86%~96%, the RSD was 0.53%~6.13%, and the linear relationship was good. The determination results of standard substances were all in uncertain range of standard values, and all of them could be used for the detection of multiple elements in feed. The determination results of graphite digestion method were significantly higher than those of other methods (P<0.05), the determination values of chromium, copper and cadmium of wet digestion method were significantly higher than those of dry ashing method and microwave digestion method (P<0.05). The study indicates that graphite digestion method integrates digestion and acid removal, and can automatically complete the digestion process according to set program. The digestion time is fixed, the work efficiency is high, and it is convenient for high-throughput sample analysis. Compared with the other three methods, the cost of equipment and consumables has great advantages.