基于溴酸钾氧化前处理的原子吸收光谱法测定饲料中铬含量研究OA北大核心CSTPCD

In this study,chromium was converted into Cr6+soluble chromium by potassium bromate pretreatment(hydrochloric acid-potassium bromate dissolution,mixed acid-potassium bromate digestion and dry ashing-potassium bromate-hydrochloric acid dissolution),and a method using atomic absorption spectroscopy to determine chromium in feed was established.The results show that the new method of hy-drochloric acid-potassium bromate digestion increased the recovery rate of chromium in Cr2O3 compared to the control groups by 94.17％,90.71％and 88.01％respectively(P＜0.05).The mixed acid-potassium bromate dissolution method increased the recovery rates of chromium in methionine chromium,chromium picolinate,chromium picolinate 1 and chromium picolinate 2 compared to dry ashing method,hydrochloric acid dissolving method,mixed acid dissolving method and dry ashing-potassium bromate-hydrochloric acid dissolving method by 96.04％,9.37％,0.08％,95.95％,96.54％,9.8％,1.71％,96.58％,63.15％,34.6％,3.03％,42.16％,76.94％,45.38％,4.79％and 20.75％respectively.The dry ashing-potassium bromate-hydrochloric acid dissolution method increased the recovery rates of chromium in piglet formula feed,concentrated feed for laying hens,micronutrient premixed feed for pigs and premixed feed for laying hens compared to the national standard dry ashing method by 13.7％,51.7％,54.41％and 70.19％respec-tively(P＜0.05).The results show that the new methods overcome the influence of insoluble chromium,volatile chromium and insoluble matter formed by dry ashing on the determination of chromium in the sample,with good linearity,low detection limit and accurate result,providing reference for accurate deter-mination of chromium in feed.