A method for detection of selenium in grain by hydride generation-atomic fluorescence spectrometry and its application / 中华地方病学杂志

ABSTRACT

Objective To establish a rapid, simple and accurate method for detection of selenium in grain that is suitable in Chinese situation. Methods Nitric acid and perchloric acid(7 3, v/v) were used to digest the grain samples by heating on a hot plate. Selenium was determined with hydride generation atomic fluorescence spectrometry. Sample detection limit, precision, accuracy(recovery, method characteristics and method control) were studied. And the grain samples of Shandong Province were determined by this method. Results The lowest detection limit was 4 μg/kg. The coefficient of correlation of working curve was 0.999 9. Intra-day precision was 1.32%, day precision was 4.17%. The total average rate of recovery was 100.5% with a range of 96.7% - 105.5%, and the average rates of recovery were 104.0%, 99.0% and 98.4% (n = 6). The determination results of corn reference material [(0.022 ± 0.006) mg/kg] were in the standard value range [(0.021 ± 0.008) mg/kg]. The determination results of the samples [(0.424 ± 0.096) mg/kg] were consistent with the results of national standard fluorescence method [(0.406 ± 0.108) mg/kg]. The contents of selenium in wheat, maize and sweet potato samples from five regions of Shandong Province wereShanting(0.030 3 ± 0.025 2),(0.016 8 ± 0.013 5),(0.015 4 ± 0.002 9) mg/kg; Anqiu(0.020 3 ± 0.000 1), (0.020 4 ± 0.009 9), (0.017 1 ± 0.007 5) mg/kg; Ju'nan(0.021 3 ± 0.013 9), (0.018 5 ± 0.007 8),(0.019 9 ± 0.003 6)mg/kg;Yishui(0.025 7 ± 0.006 2),(0.020 6 ± 0.003 2), (0.018 2 ± 0.003 2) mg/kg; Wulian(0.020 3 ± 0.004 7), (0.020 1 ± 0.008 9), (0.018 4 ± 0.007 3) mg/kg. Conclusions The method has the advantages of higher precision and accuracy, less time, less pollution, less aciduse, easier operation and repeatability.It is very suitable for measuring selenium content in large amount of food samples.