Yoshida M, Kimura Y, Abe M, Ando T, Tachi H, Fukunaga K
Department of Biotechnology, Faculty of Engineering, Kansai University, Suita, Osaka, Japan.
J Nutr Sci Vitaminol (Tokyo). 2001 Jun;47(3):248-52. doi: 10.3177/jnsv.47.248.
For determination of selenium (Se) in biological materials, an improved method based on high performance liquid chromatographic determination of the fluorophore formed by reaction of selenite with 2,3-diaminonapththalene was developed. The concentration detection limits were 0.5 ng/g in dried materials and 0.03 ng/mL in fluid materials. In quadruplicate assays of 11 biological reference materials using the proposed method, measured Se concentrations were not significantly different from their certified values. Thus, the proposed method is reliable and suitable for the determination of trace levels of Se in foods. Using the proposed method, Se concentrations in various kinds of tea were determined to assess the contribution of tea to daily Se intake in the Japanese population. Se concentration in the leaves of general black, green and oolong tea obtained in local retail stores was 33 +/- 19 ng/g (n=440). The leaves of a particular Chinese green tea sold under the name "high Se tea" were found to contain 455 +/- 184 ng/g (n= 14) of Se. While the percentage of Se extractable by infusion was less than 5% for the general teas, that in the high Se tea was more than 20%. These results indicated that intake of tea does not contribute to daily Se intake in the Japanese population. However, since infusions from high Se tea contained over 5 ng/mL of Se, consumption of over 1 L/d of tea derived from such high Se teas may increase the daily Se intake by close to 10%.
为了测定生物材料中的硒（Se），开发了一种基于高效液相色谱法的改进方法，该方法用于测定亚硒酸盐与2,3-二氨基萘反应形成的荧光团。干燥材料中的浓度检测限为0.5 ng/g，液体材料中的浓度检测限为0.03 ng/mL。使用该方法对11种生物参考材料进行四次重复测定，测得的硒浓度与其认证值无显著差异。因此，该方法可靠，适用于食品中痕量硒的测定。使用该方法测定了各种茶叶中的硒浓度，以评估茶叶对日本人群每日硒摄入量的贡献。当地零售店购买的普通红茶、绿茶和乌龙茶叶片中的硒浓度为33±19 ng/g（n = 440）。一种名为“高硒茶”的特定中国绿茶叶片中硒含量为455±184 ng/g（n = 14）。普通茶叶通过冲泡可提取的硒百分比小于5%，而高硒茶中该比例超过20%。这些结果表明，茶叶摄入对日本人群的每日硒摄入量没有贡献。然而，由于高硒茶冲泡液中硒含量超过5 ng/mL，每天饮用超过1 L这种高硒茶泡的茶可能会使每日硒摄入量增加近10%。
