Mino Y, Ota N
Osaka University of Pharmaceutical Sciences, Japan.
Chem Pharm Bull (Tokyo). 1990 Aug;38(8):2208-11. doi: 10.1248/cpb.38.2208.
Energy-dispersive X-ray fluorescence spectrometry following sample decomposition and preconcentration was developed to determine selenium in crude drugs. Samples were decomposed with conc. HNO3 and conc. H2SO4 in a flask with a reflux condenser. Evaporation of HNO3 had to be avoided to prevent serious loss of this element. Selenium was preconcentrated from the digestion liquid by two-step reduction with 4M HCl and ascorbic acid, the elemental selenium formed was adsorbed on activated carbon and then collected on a Nuclepore membrane filter for direct irradiation in an X-ray spectrometer. This analytical method (detection limit, 0.03 ppm) was used to determine selenium in many kinds of crude drugs. The analytical results indicated vegetable drugs to be low in selenium content: more than 0.5 ppm in only a limited number of samples and less than detection limit (0.03 ppm) in nearly all the samples. Animal drugs contain selenium at higher levels, Lumbricus and Cantharis being 7.46 and 1.67 ppm, respectively.
建立了样品分解和预富集后能量色散X射线荧光光谱法测定中药材中的硒。样品在带有回流冷凝器的烧瓶中用浓硝酸和浓硫酸分解。必须避免硝酸蒸发以防止该元素严重损失。通过用4M盐酸和抗坏血酸两步还原从消化液中预富集硒，形成的元素硒吸附在活性炭上，然后收集在核孔膜过滤器上，以便在X射线光谱仪中直接照射。该分析方法（检测限为0.03 ppm）用于测定多种中药材中的硒。分析结果表明植物药中的硒含量较低：仅有限数量的样品中硒含量超过0.5 ppm，几乎所有样品中的硒含量均低于检测限（0.03 ppm）。动物药中的硒含量较高，地龙和斑蝥中的硒含量分别为7.46 ppm和1.67 ppm。
