Laboratory adaptation of the methylene blue method to flow injection analysis: towards in situ sulfide analysis in hydrothermal seawater

This preliminary study presents the laboratory adaptation of the methylene blue method for the analysis of sulfide in hydrothermal seawater to flow injection analysis (FIA) before its integration on an in situ analyser. The manifold used after optimisation enables us to work on a 0–450 µmol l–1 sulfide range with a detection limit between 0.1 and 0.4 µmol l–1 and a relative standard deviation < 1%. The following steps will be the adaptation of the manifold on the in situ analyser and field tests.