氢化物发生－缝管原子捕集－原子吸收法测定钢铁和地质试样中的砷

Atomic Absorption Spectrometric Determination of Arsenic in Steel and Geological Samples Using Hydride Generation Combined with Slotted Tube Atom-trap Technique

介绍简易的氢化物发生原子吸收测砷的方法。喷雾器负压将ＫＢＨ_４吸入反应器，并将生成的ＡｓＨ_３吸入乙炔－空气焰原子化。石英缝管使灵敏度提高３．５倍。方法的检测限（３σ）为１．８ｎｇ／ｍＬ（５ｍＬ试样）。２０ｎｇ／ｍＬＡｓ（Ⅲ）标准液１０次测定的ＲＳＤ为３．８％。本法成功地应用于钢铁和地质标样中微量砷的测定。

A simple device for hydride generation-atomic absorption spectrometric determination of arsenic is described.KBH4 was sucked,by the negative pressure of the nebulizer,into a.batch- wise hydride generator.The generated arsine was then aspirated into air-acetylene flame for atomization.A slotted quartz tube was employed to trap atoms,resulting in a 3.5- fold increase in sensityvity.Under optinum conditions,the detection limit(3σ)for 5mL sample is 1.8ng/mL As(Ⅲ).Ten runs of a 20 ng/mL As(Ⅲ)standard solution gave a RSD of 3.8%,The developed method has been successfully applied to the determination of trace arsenic in steel and geological samples.