微波消解-石墨炉原子吸收法测定黄豆样品中的硒

摘要

以黄豆为研究对象,建立了微波消解-石墨炉原子吸收光谱法测定黄豆中总硒含量的方法,研究不同微波消解溶剂和消解条件对含硒黄豆消解效果的影响,优化石墨炉原子吸收光谱法测定条件.测定结果显示,最佳消解剂:HNO3-H2O2;最佳微波消解条件为第一工步:1 min、0.5 MPa;第二工步:2 min、1.0 MPa;第三工步:3 min、1.5 MPa;最适基改剂为3μL 1%硝酸镍,石墨炉最佳灰化温度和原子化温度分别为800℃和2 300℃.在优化试验条件下,该方法测定硒的线性范围为0~250μg/L,检出限为1.20μg/L,空白样品的相对标准偏差(n=10)为3.86%,回收率为96.46%~103.7%.%The selenium content in soybeans were determined by Microwave Digestion-Graphite Furnace Atomic Absorption Spectrometry(GF-AAS). The effects of digestive reagent and digestion conditions on sample preparation were discussed and the determination conditions by GF-AAS were optimized.The sample was ingested with high-pressure closed vessel using nitric acid-hydrogen peroxide as solvent. The best Microwave Digestion procedure:(1)1 min, 0.5 MPa;(2)2 min, 1.0 MPa;(3) 3 min,1.5 MPa;3μL 1%Ni(NO3)2 were selected as chemical modifiers to increasing the thermostability of selenium , and the pyrolysis temperature and the atomization temperature were seted at 800℃and 2 300℃, respectively. under the optionmal condition, the calibration curve showed a good linear relationship between the adsorption peak area and selenium concentration in the range of 0-250μg/L with a detection limit of 1.20μg/L. The relative standard deviation ( n=10) of blank sample was 3.86%and recoveries varied from 96.46%to 103.7%.