Graphite furnace atomic absorption spectrometric determination of nickel at sub-ng g–1 levels in marine samples by carbonyl generation with in situ pre-concentration

Abstract

Reduction of Ni^II in solution by addition of BH₄^– and its carbonylation in a stream of CO-Ar serves to transfer the volatile Ni(CO)₄ from a generation cell to a pre-heated graphite furnace where it undergoes decomposition and deposition at T > 500 °C. Subsequent atomisation at T > 2700 K and measurement of the atomic absorption serves to quantify Ni in test samples by direct comparison with signals derived from identically treated solutions of standards. The system is ca. 80% efficient and is characterised by a concentration detection limit (3σ) of 4 ng l^–1, based on a 10-ml test sample. Results are presented for the analyses of several natural water and biological reference materials.