直流等离子体光源的一种低氩雾化系统

A LOW ARGON NEBULIZING SYSTEM FOR DIRECT CURRENT PLASMA SOURCE

本工作对降低直流等离子体(DCP)光源的耗氩量进行了研究。以玻璃同心雾化器,旋流雾化室组成的雾化系统,当送样管口径在2.4—3.3mm时可和DCP光源匹配形成较稳定的等离子焰,其检出限、稳定性和原雾化系统相当,而氩只需4—5升/分,比原光源耗氩量降低约40％。研究了锂、铝和磷酸盐的基体效应,并对基体效应的产生作了讨论。

An investigation to reduce the consumption of argon in direct current plasma (DCP) source has been carried out. A glass concentric nebulizer coupled with a cyclone spray chamber was used as the new nebulizing system. When the diameter of the sample inlet tube is reduced to 2.4—3.3 mm, a relatively stable DCP can be formed only using 4—5 L/min of argon (ca. 40％ lower than the original consumption). The resulting detection limit and stability are comparable with those of the original system. An investigation of the matrix effect shows that: (1) The enhancing effect of Li salt on the spectral line intensity is similar in both new and original systems. (2)With regard to the influence of phosphate on Ca the intensity of Ca ionic line is enhanced,while that of atomic lines is reduced in both systems.(3) Concerning influence of Al on Ca, the intensity of Ca ionic lines is enhanced, but that of atomic lines is reduced, especially in the proposed nebulizing system.