SIMULTANEOUS DETERMINATION OF GERMANIUM, ARSENIC, TIN AND ANTIMONY WITH TOTAL-REFLECTION X-RAY FLUORESCENCE SPECTROMETRY USING THE HYDRIDE GENERATION TECHNIQUE FOR MATRIX SEPARATION - FIRST STEPS IN THE DEVELOPMENT OF A NEW APPLICATION

摘要

This paper introduces a new perspective for total-reflection X-ray fluorescence analysis (TXRF), that is the simultaneous determination of Ge, As, Sn and Sb in seawater. As is well known from atomic absorption spectroscopy (AAS) and inductively coupled plasma techniques (ICP) compounds of these elements can be reduced by sodium borohydride to their hydrides and thus separated from the matrix. In this work the hydride generation is used for matrix separation in TXRF measurements. For this purpose the following procedures are considered: (1) Preconcentration of hydrides by absorption in solvents, and evaporation of some mu l of this solution on the sample carrier. (2) Decomposition of hydrides in a heated thin silica tube, or at rough and/ or catalytically active surfaces, e.g, in adequately prepared columns, eluting of the species by acid and evaporation of some mu l of this solution on the sample carrier. (3) Decomposition of hydrides directly on the surface of a heated silica sample carrier as a thin amorphous film. (4) Combustion of hydrides in the hydrogen flame and deposition of an elemental film on the sample carrier. Basically, all four ways have been tested and the results are promising. (C) 1997 Elsevier Science B.V. [References: 51]