摘要
目的基于在HCl介质中硒对H_2O_2氧化甲基红有较强的催化作用,建立了测定亚硒酸钠片中硒含量的新方法。方法在2支具塞比色管中,各依次准确加入甲基红溶液2.0 mL(300μg/mL)、H_2O_2溶液2.5 mL(3%)、盐酸溶液2.0 mL(1 mol/L),于其中1支比色管加入一系列不同浓度的硒标准溶液,另1支作试剂空白。在80℃水浴10 min,冷却后,用1 cm比色皿在波长518 nm处,以蒸馏水为为参比,分别测定测定其ΔA。结果硒在0.2~1.2μg/mL之间存在线性关系,线性方程为ΔA=0.263C+0.0117(r^2=0.9988),检出限为0.186μg/mL,表征摩尔吸收系数为2.35×10~5 L/(mol·cm)。结论将该方法用于亚硒酸钠片中硒的含量测定,与2,3-二氨萘荧光法比较结果准确可靠、操作简便。
Objective To establish a new method for the determination of selenium in sodium selenite tablets based on the strong catalytic effect of selenium on the oxidation of methyl red by H2O2 in HCl medium. Methods Totally 2.0 mL （300 μg/mL） of methyl red solution, 2.5 mL （3%） of H2O2 solution and 2.0 mL （1 mol/L） of hydrochloric acid solution were added into each of two plugged colorimetric tubes. One colorimetric tube was added a series of different concentrations of selenium standard solution, with the other as a reagent blank. After cooled at 80 ℃ for 10 min, the linearity of ΔA was determined at a wavelength of 518 nm with distilled water as the reference. Results Selenium has linear relationship in the range of 0.2~1.2 μg/mL. The linear equation was ΔA=0.263C＋0.0117 （r2=0.9988）. The limit of detection was 0.186 μg/mL. The molar absorption coefficient was 2.35×105 L/（mol·cm）. Conclusion Comparison with 2,3-diamine fluorescence method, this method is accurate, reliable and easy to operate, which can be used to determine the content of selenium in sodium selenite tablets.
作者
白静
崔丽伟
BAI Jing 1, CUI Li-Wei2(1. Faculty of Chemical Engineering, Henan College of Applied Technology, Zhengzhou 450001, China; 2. School of Food Engineering, Henan Animal Husbandry Economics College, Zhengzhou 450046, Chin)
出处
《食品安全质量检测学报》
CAS
2018年第5期1002-1006,共5页
Journal of Food Safety and Quality
关键词
硒
催化光度法
H2O2-甲基红
亚硒酸钠片
selenium
catalytic spectrophotometry
H2O2-methyl red
sodium selenite tablets
