环己烷萃取-微波消解-原子荧光光谱法测定白米中硒含量的方法研究

Research on Determination of Content of Selenium in White Rice by Cyclohexane Extraction-Microwave-Digestion-Atomic Fluorescence Spectrometry

建立了环己烷萃取-微波消解-原子荧光光谱法测定白米中有机硒和无机硒含量的方法。利用正交试验确定了检测仪器的最佳参数,并采用环己烷作为萃取剂,使用硝酸、过氧化氢进行微波消解预处理,运用氢化物发生-原子荧光光谱法测定总硒和无机硒的含量。试验结果表明,该检测方法在硒质量浓度为0~10μg/mL的范围内,有良好的线性关系,检出限为0.0072μg/mL,相对标准偏差为2.38%(n=8),回收率达95%~105%;该方法所用仪器设备简单,重复性好,能满足当地产白米中无机硒和有机硒含量的测定要求。

In this paper,a method for the determination of organic selenium and inorganic selenium in white rice by cyclohexane extraction-microwave digestion-atomic fluorescence spectrometry is established.Orthogonal experiment is used to optimize the detection parameters of the instrument,and the classification of inorganic selenium and organic selenium is explored by cyclohexane extraction.The samples are pretreated by microwave digestion with nitric acid and hydrogen peroxide,and the total selenium content determined by hydride generation-atomic fluorescence spectrometry.The results show that the method has good linearity in the range of 0~10μg/mL,the correlation coefficient R is 0.9991,and the detection limit is 0.0072μg/mL.The relative standard deviation is 2.38%(n=8),and the recovery rate is 95%~105%.The method is fast and the equipment used is simple,which can meet the requiremet of determination of organic selenium content in local white rice.