Methylmercuric complexes in aquatic systems.

Abstract Equilibrium calculations indicate that methylmercuric ion is almost completely complexed under conditions that exist in fresh waters. Sulfur-bonded complexes, CH3HgS−, (CH3Hg)2S, and CH3HgSR, are likely to be the predominant forms of methylmercury in fresh natural waters. With no reduced sulfur species or sulfhydryl-containing organics present, methyl-mercuric hydroxide or methylmercuric chloride would predominate. Common chemical species such as orthophosphate, ammonia, phenolic groups, and protein amino groups have little effect upon complexation of methylmercury.