Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey.
Talanta. 2012 Dec 15;102:59-67. doi: 10.1016/j.talanta.2012.06.002. Epub 2012 Jun 9.
Speciation of tellurium can be achieved by making use of different kinetic behaviors of Te(IV) and Te(VI) upon their reaction with sodium borohydride using hydride generation. While Te(IV) can form H(2)Te, Te(VI) will not form any volatile species during the course of hydride formation and measurement by atomic absorption spectrometry. Quantitative reduction of Te(VI) was achieved through application of a microwave assisted prereduction of Te(VI) in 6.0 mol/L HCl solution. Enhanced sensitivity was achieved by in situ trapping of the generated H(2)Te species in a previously heated graphite furnace whose surface was modified using Pd or Ru. Overall efficiency for in situ trapping in pyrolytically coated graphite tube surface was found to be 15% when volatile analyte species are trapped for 60s at 300°C. LOD and LOQ values were calculated as 0.086 ng/mL and 0.29 ng/mL, respectively. Efficiency was increased to 46% and 36% when Pd and Ru surface modifiers were used, respectively. With Ru modified graphite tube 173-fold enhancement was obtained over 180 s trapping period with respect to ETAAS; the tubes could be used for 250 cycles. LOD values were 0.0064 and 0.0022 ng/mL for Pd and Ru treated ETAAS systems, respectively, for 180 s collection of 9.6 mL sample solution.
利用碲（IV）和碲（VI）与硼氢化钠反应时的不同动力学行为，可以实现碲的形态分析。在形成氢化物的过程中，碲（IV）可以形成 H 2 Te，而碲（VI）在原子吸收光谱法测量过程中不会形成任何挥发性物质。通过在 6.0 mol/L HCl 溶液中应用微波辅助预还原 Te(VI)，可以实现 Te(VI)的定量还原。通过将生成的 H 2 Te 物种原位捕获到先前加热的石墨炉中，可以实现灵敏度的增强，该石墨炉的表面使用 Pd 或 Ru 进行了修饰。在热解涂层石墨管表面进行原位捕获时，挥发性分析物物种在 300°C 下捕获 60s 的总体效率为 15%。LOD 和 LOQ 值分别计算为 0.086 ng/mL 和 0.29 ng/mL。当使用 Pd 和 Ru 表面修饰剂时，效率分别增加到 46%和 36%。在 Ru 修饰的石墨管中，在 180 s 的捕获期内相对于 ETAAS 获得了 173 倍的增强，该管可以使用 250 个循环。对于 Pd 和 Ru 处理的 ETAAS 系统，在收集 9.6 mL 样品溶液 180 s 的情况下，LOD 值分别为 0.0064 和 0.0022 ng/mL。
