氢化物发生-电感耦合等离子体发射光谱法测定铀矿地质样品中痕量硒

采用氢化物发生技术测定地质样品中的硒时,需要考虑样品的溶解、Se价态的预还原以及抑制共存离子的干扰。本文采用硝酸-盐酸-氢氟酸-高氯酸体系快速溶解样品,直接加入浓盐酸煮沸将六价硒还原为四价硒,将氢化物发生器与电感耦合等离子体发射光谱仪联用测定了铀矿地质样品中的痕量硒。样品中除了Cu2+其他离子的含量均不干扰硒的测定,通过在试液中加入铁盐溶液或在硼氢化钠还原剂中加入铁氰化钾抑制了Cu2+的干扰。方法检出限为0.12μg/L,精密度(RSD)小于5%。与前人报道的方法相比,本方法检出限较低,操作简单快速,冲洗30 s可消除记忆效应,适合批量铀矿地质样品中痕量硒的测定。

Determination of Trace Selenium in Uranium-bearing Geological Samples by Hydride Generation-Inductively Coupled Plasma-Optimal Emission Spectrometry

X-Ray Fluorescence spectrometry (XRF) method was developed for the determination of 10 major elements, such as silicon, aluminum, calcium and magnesium,in different type rocks. The calibration curves were determined from 28 different type rock standards which were fused into glass beads. The matrix effect was calibrated by using empirical factors. This method was used for determining the 10 major elements of samples from GeoPT proficiency testing. The 23 different type rock samples were analyzed in 15 years and the results suggested that this method is most effective in determining SiO₂, Al₂O₃, K₂O and CaO (the obtained |Z|<2 for the all samples), and more effective in determining MgO, MnO, TiO₂ and Na₂O though each element have only one suspect result in different samples (the obtained |Z|>2). When the content of TFe₂O₃ large than 1.00% and P₂O₅ between 0.08% and 0.80%, the results can match our expectation (the obtained |Z|<2). To sum up, the developed XRF method has long term stability and is effective in analyzing rock samples, which can match the expectation of applied geochemistry laboratories for determination of 10 major elements in different type rock samples.