New concept for hydride generation technique: electrochemical hydride generation

Abstract

A new hydride generation system for atomic absorption or inductively coupled plasma atomic emission spectrometry is described. The system based on electrochemical hydride generation uses a miniaturized continuous running cell with Pt electrodes. The anode and cathode compartments are separated by a Nafion membrane. The anolyte (2 mol l^–1 H₂SO₄) circulates after separation of the oxygen formed at the anode. The hydrides formed at the cathode are separated by a membrane gas–liquid separator. The small geometric dimensions allow the flow rate of the catholyte (diluted H₂SO₄ or HCl) to be extremely low. Therefore, the consumption of expensive high-purity acids is lower than in conventional hydride generation systems. The entire system fulfils the requirements of flow injection analysis. This technique achieves high sample throughput and low sample volumes (100 µl). The influence of transition metals of Groups 8, 9, 10 and 11 are investigated and can be eliminated for most of the applications.