MP-AES法测定水产饲料中多种金属元素

应用微波等离子体发射光谱(microwave plasma-atomic emission spectrometry，MP-AES)技术，建立水产饲料中铜、铁、锰、锌、钾、钠等元素MP-AES分析方法。样品采用干灰化法消解，开展了方法学研究试验，同时与AAS和ICP-AES方法进行比对，并完成FAPAS能力验证样品和标准物质确证试验。通过优化MP-AES仪器的各项参数，在所选定的条件下，各元素的线性相关系数在0.999以上，检出限在0.4～3.9 mg·kg-1之间，加标回收率在103%～112%之间，精密度试验相对标准偏差在0.2%～0.6%之间;测定结果与AAS法、ICP-AES法比对，单因素方差分析(α=0.05)各元素P值在0.065～0.438之间，均大于0.05，无显著性差异;FAPAS奶牛饲料能力验证和灌木枝叶(GBW07602)标准物质确证试验的各元素测定值均在参考值范围内。结果表明，所建立的方法简单、快速，线性范围宽，具有良好的准确性和精密度;MP-AES无需使用乙炔、氩气，安全、经济、环保，能降低检测成本、提高检测效率，可替代AAS、ICP-AES法测定水产饲料中的六种金属元素，为水产饲料的质量控制提供理想的元素分析方法。

Determination of Multi-Elements in Aquatic Feed by Microwave Plasma-Atomic Emission Spectroscopy

In the present research, a novel method for quantitative analysis of multi-elements (Cu, Fe, Mn, Zn, K and Na) in aquatic feed was established by using microwave plasma-atomic emission spectroscopy (MP-AES) technology. The sample was pretreated by traditional dry ashing method, and then a series of methodological study experiments, such as the detection limit, the spiked recovery, the precision measurement, the method comparison with AAS and ICP-AES, the standard substance confirmation and so on, were accomplished by MP-AES. The instrument parameters of MP-AES were optimized. In the optimal conditions, the linear calibration curve was established for each element, and the linear regression correlation coefficient was more than 0.999. The limit of detection (LOD) was between 0.4 and 3.9 mg·kg-1. The spiked recovery was between 103% and 112%.The relative standard deviation of precision measurement was between 0.2% and 0.6%. In the method comparison, the one way ANOVA statistical analysis yielded the p value between 0.065 and 0.438, which were greater than 0.05, there was no statistically significant difference among MP-AES, AAS and ICP-AES. The FAPAS 10102 dairy ration test material and the national standard substances (GBW07602) were prepared for method confirmation in this study, and the measured values were in good agreement with the certified values. Compared with the commercial ICP-AES which typically uses argon as the plasma gas, the MP-AES relies on using nitrogen as the plasma gas, which may provide a more economical alternative to traditional ICP-AES for routine analysis in feed analytical laboratories. The established method was simple, fast, reproducible and accurate, and it was an ideal analysis technique to substitute AAS and ICP-AES for the determination of multi-elements in aquatic feed.