Determination of reduced sulfur compounds by high-performance liquid chromatography in hydrothermal seawater and body fluids from Riftia pachyptila

Abstract

This paper describes a method for the determination of reduced sulfur compounds in hydrothermal seawater and body fluids from the hydrothermal tube worm Riftia pachyptila. Sulfur is a key component of the hydrothermal ecosystem based on chemosynthesis. Sulfur compounds were derivatized at pH 8 (4.3 for sulfide in biological fluid) with a fluorescent reagent, monobromobimane, and separated by reverse-phase HPLC. The eluted compounds were detected by spectrofluorimetry. This method allowed the quantitative analysis of sulfide, sulfite, thiosulfate, cysteine and glutathione in seawater, vascular blood and coelomic fluids from R. pachyptila. The detection limits were in the 0.1 µmol l^–1 range with a precision lower than 10%. The method has been applied to hydrothermal seawater. The organisms are distributed along a gradient of sulfide (produced by the vent) and thiosulfate. Analysis of biological fluid was performed with a new sample treatment allowing the analysis of total sulfide (free and bound to haemoglobin) with results comparable to published methods.