CONSTANTS OF MERCURY METHYLATION AND DEMETHYLATION RATES IN SEDIMENTS AND COMPARISON OF TRACER AND AMBIENT MERCURY AVAILABILITY

摘要

A method was developed to measure mercury methylation and demethylation rate constants simultaneously in aquatic samples. Solutions containing stable isotope tracers of ~199Hg~2+ and CH_2~202Hg+ were spinked into lake sediments at subambient concentrations. The formation of CH_3~199Hg~+ and the decrease in CH_3~202Hg~+ were measured simultaneously in time experiments using gas chromatographic separation and isotope-specific detection by inductively coupled plasma spectrometry.