Analysis of nickel–aluminium bronze crevice solution chemistry using capillary electrophoresis

A new approach has been developed to simultaneously analyse the evolution of metallic cation and inorganic anion solution concentrations within a crevice micro-environment using capillary electrophoresis. The chemical conditions within a Cortest crevice assembly have been studied when the bold surface of nickel–aluminium bronze was exposed to a bulk 3.5% (0.6 M) NaCl solution. The crevice solution chemistry was assessed intermittently over a period of 6 months. Capillary electrophoresis was used since it is capable of analysing nanolitre solution volumes with widely disparate concentrations of species. A methodology has been optimised for the first time to simultaneously evaluate inorganic anion and metal cation crevice solution composition, without the need for extensive sample pre-treatment. Analyses for chloride and a range of metal cations, including Cu2+, Ni2+ and Fe3+ are presented.