过渡金属元素氢化物发生-原子荧光增敏效应研究

基于反应介质酸度对Zn,Cd,Cu和Ni的氢化物发生影响的考察,揭示了氢转移过渡中间态H BH4-]*分解反应氢化物生成机理。分别考察了Co2 离子、Ni2 离子、邻菲咯啉、羟基喹啉对Zn,Cd,Cu和Ni氢化物发生原子荧光信号的影响,探讨了其增敏机理。由于Co和Ni的挥发性物种分解抑制了Cd和Zn氢化物在传输过程中的分解损失,明显提高了Cd和Zn氢化物的传输效率。邻菲咯啉与Co2 离子或8-羟基喹啉与Co2 离子对Zn和Cd信号均具有协同增敏效应,8-羟基喹啉和邻菲咯啉对Zn和Cd信号则没有协同增敏效应。考察了阳离子、阴离子和非离子表面活性剂对氢化物发生的促进作用。结果证实阳离子和非离子表面活性剂均对分析物信号有明显的增敏效果,其原因在于表面活性剂的存在引起溶液的表面张力显著的降低。以石墨炉原子吸收法进一步考察了分析物从表面活性剂吸收液中逸出特性,提出了表面活性剂在氢化物发生和传输过程中的增敏机理。

Investigation of Enhancing Effect for Hydride Generation-Atomic Fluorescence of Transition Metal Elements

A mechanism of hydride generation based on disassembly reaction of hydrogen-transferred interim state M(BH4)m]* was developed by investigating the effect of reaction medium acidity on hydride generation.The effects of Co2 and Ni2 ,phenanthroline and 8-hydroxyquinoline on hydride generation-atomic fluorescence signals of Zn,Cd,Cu and Ni were studied,respectively,and their enhancing mechnism was discussed.The enhancing effect Co2 and Ni2 on the fluorescence signals of Zn and Cd was due to the increase in transmission efficiency of hydride of Zn and Cd.There was a synergic enhancing effect between phenanthroline or 8-hydroxyquinoline and Co2 on the fluorescence signals of Zn and Cd,however no synergic enhancing effect between phenanthroline and 8-hydroxyquinoline on the fluorescence signals of Zn and Cd.The simulative action of cationic surfactant,anion surfactant and non-ionic surfactant surfactant to hydride generation was investigated.It is shown that both cationic surfactant and nonionic surfactant have obvious enhancing effect on the fluorescence signals of analytes because of the decrease in surface tension of reaction solution.The release characteristics of hydride from the absorption solution containing surfactant was ulteriorly examined by using graphite furnace atomic absorption spectrometry,and the mechanism of enhancing effect of surfactant on hydride generation and transmission was proposed.