La matrice eau de mer et le signal du cuivre en spectrometrie d'absorption atomique sans flamme: Partie 2: Proposition d'un schéma explicatif des phénomènes observés pour une eau de mer

(Copper signals from seawater matrices in electrothermal atomic absorption spectrometry. Part 2: model for phenomena observed with sea water.)A model to explain the variations of copper signals in seawater is proposed on the basis of the results of Part 1 of this study and data obtained by ashing simulated seawaters under different conditions. The model is confirmed by the results found with nitric of sulfuric acid as modifier. In this model, ashing at 800°C hydrolyses MgCl₂ to MgO, and the consequent formation of sodium sulfide from the matrix stabilizes the copper in the furnace. The addition of a small nitrate concentration (0.2 M) induces, when magnesium is present, a complementary decrease of the interference.