管表面性质对Ag,Pb和V原子化的影响——石墨炉原子化器中原子化过程的研究(Ⅶ)

Influence of Surface Property of Tube on Atomization of Ag, Pb and V——Study on Atomization Process in Graphite Furnace Atomizer (Ⅶ)

研究和比较了普通石墨管,热解涂层和全热解石墨管中Ag,Pb和V原子吸收曲线形状、原子消失速度和分析灵敏度。实验表明,普通石墨菅中Ag,Pb和V的吸收曲线较宽,由于Ag和V与碳形成相应的Ag_2C_2和VC,原子消失呈现复杂的偶联扩散过程。全热解石墨管中Ag,Pb和V的吸收曲线较窄,基本上不形成Ag_2C_,VC的形成受到很大的抑制,钒的分析灵敏度有明显的提高。

The atomization behavior of Ag, Pb and V have, for comparison and study, been atomized off the wall of tube. The experiments showed that the absorption curves broadened and complex process coupled with diffusion was observed in the standard graphite tube because Ag and V form Ag_2C_2 and VC with graphite which have lower vapour pressure than the elements alone. But the absorption peaks are sharper and no formation of Ag_2C_2 was observed and the formation of VC largerlly was restrained in a tatolly pyrolytic graphite tube. So a larger enhancement of analytical sensitivity for determination of vanadium in tatolly pvrolytic graphite tube.