[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 con- ditions, 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.