Quantification of germanium in organometallics compounds by total-reflection X-ray fluorescence

摘要

This work presents the study carried out to evaluate quantitatively the germanium content in organometallic materials by mean of Total-reflection X-Ray Fluorescence (TXRF). Samples were prepared by using different acid mixtures; aqua regia, HNO3 and H2O:HF:HNO3 (1:1:1) and different digestion processes; open vessel and microwave-assisted digestion. Germanium recoveries, as poor as 0.05%, were obtained after the measure of the initial acid digestions by mean of TXRF and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In this way, direct solid sample preparation methodology combined with TXRF technique (DSA-TXRF) was applied and compared with the results obtained by mean of acid digestion. DSA-TXRF procedure proved to be adequate avoiding Ge loses by volatilization, or precipitation, and reaching an average analytical recovery of 95.4%. The acid mixture H2O:HF:HNO3 (1:1:1) by using open vessel digestion was also adequate for Ge quantification by TXRF and ICP-MS obtaining average analytical recoveries of 98.8% and 99.2% respectively and therefore validating the DSA-TXRF developed procedure.