不同前处理方法对火焰原子吸收光谱法测定饲料中铜含量的影响

目的通过比较不同的样品前处理方法,建立一种火焰原子吸收光谱法测定饲料中铜的含量。方法以饲料样品为原料,微波消解、湿法消解和干法灰化前处理方法分别对样品前处理后,采用火焰原子吸收光谱法测定饲料样品中铜的含量。结果 3种前处理方法测得的饲料中铜含量的加标回收率为92.0%~108%,在测定质控样品时,微波消解和湿法消解测定结果的相对标准偏差为1.3%~2.3%,符合要求;但干法灰化测定结果的相对标准偏差最大值为11.0%,超出标准范围。结论微波消解和湿法消解均能得到准确的检测结果,但湿法消解存在试剂消耗多、消解时间长等问题,而微波消解相对快速、准确、精密度高,更适合作为日常实验时饲料中铜的测定分析方法。

Effects of different pretreatment methods on determination of copper content in feed by flame atomic absorption spectrometry

Objective To establish a method for determination of copper content in feed by flame atomic absorption spectrometry by comparing different pretreatment methods. Methods Feed samples were used as raw materials, and pretreated by microwave digestion, wet digestion and dry pre-treatment. The copper content in feed samples was determined by flame atomic absorption spectrometry. Results The standardized recoveries of copper content in feed measured by 3 pretreatment methods were 92.0%~108%. When measuring quality control samples, the relative standard deviations of microwave digestion and wet digestion were 1.3%~2.3%, which meeting the requirements. But the maximum value of relative standard deviation of dry ashing test results was 11.0%, which was beyond the standard range. Conclusion Both microwave digestion and wet digestion can get accurate test results, but the wet digestion has some problems, such as too many reagent consumption, digestion time, so microwave digestion is relatively fast, accurate, high precision, and more suitable for daily test on the determination of copper in feed as an analysis method.