MECHANISM OF THE REACTION BETWEEN DIPHENYL MERCURY AND METHYL MERCURY-CHLORIDE - STUDY USING LIQUID-PHASE CHROMATOGRAPHY

Reversed phase liquid chromatography is used to elucidate the mechanism of the reaction between diphenyl mercury (DPM) and methyl mercury chloride (MMC). In a first part, the organomercurials are eluted directly with the following mobile phase: Methanol/NaCl (0.05 M) 70/30 (v/v). In these conditions, quantitative analysis of the reaction mixture shows that DPM concentration becomes constant after 10 min. In the other hand, the phenyl mercury chloride (PMC) obtained and the DPM consumed are the same. These results suggest a chemical equilibrium when DPM reacts with MMC. This equilibrium was also proved by a second method. It includes a complexation on column of the organomercurials by adding 6 marcaptopurine in the following mobile phase methanol / acetonitril/KH2PO4 0.005 M (1/4/5 v/v). The equilibrium constants obtained with the two methods are quite comparable.