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目的建立一种快速准确实用并能推广应用的氢化物原子荧光光谱法测定食品中硒的方法。方法优化样品消解条件,并且采用石墨消解仪二次加热方式同时消解样品和标准曲线,使样品称量、消化、定容在同一消解管内进行。消解食品样品不用冷消化过夜,标准曲线系列和样品经石墨消解仪消解2 h~3 h后可直接用于测定。结果硒含量在0μg/L~50μg/L范围内线性关系良好,相关系数r≥0.999,检出限为0.12μg/L,样品测定相对标准偏差RSD为1.5%~6.9%,回收率为96%~103%。质控样结果在证书范围内。结论方法改进后可明显缩短样品处理时间,减少样品消解时酸用量,精密度和准确度达到要求,是快速准确的测定食品中硒的方法。
OBJECTIVE To establish a rapid, accurate and practical method for the determination of selenium in food by hydride generation atomic fluorescence spectrometry. Methods The sample digestion conditions were optimized, and the sample and standard curve were digested simultaneously by the second heating method of graphite digester, so that the samples were weighed, digested and fixed in the same digestion tube. Digestion of food samples without cold digestion overnight, the standard curve series and sample digestion by graphite digestion after 2 h ~ 3 h can be used directly for the determination. Results The linearity of selenium content in the range of 0μg / L ~ 50μg / L was good with a correlation coefficient of r ≥ 0.99 and a detection limit of 0.12μg / L. The relative standard deviations (RSDs) were 1.5% ~ 6.9% and the recoveries were 96% ~ 103%. Quality control sample results within the scope of the certificate. Conclusion The improvement of the method can obviously shorten the sample processing time, reduce the amount of acid used in digestion, and meet the requirements of precision and accuracy. It is a fast and accurate method for the determination of selenium in food.