Diphenylmercury determination

A further kinetic investigation of the rates of cleavage of diphenylmercury (and some dialkylmercurials) showed similar kinetic features608. The first-order rate for the reaction of diphenylmercury with acetic acid at 25 °C was 4.98 x 10", which agreed quite well with the value from the above determination (2 x 10-4 at 42 °C with dioxan). In the presence of perchloric acid, second-order kinetics were found to be obeyed (for dineophyl mercury and presumably for diarylmercurials as well) for a twofold concentration change in both mercurial and perchloric acid. Two separate mechanisms were proposed for the reactions in the absence, and presence, of perchloric acid. Under the former conditions an SEi process (244) was... 

The cleavage of diphenylmercury in acetic acid with perchloric acid, and the reaction of dialkylmer-cury with mercury nitrate, may be considered as exhibiting the pure 5e2 mechanism, where an attack of the electrophile at the metal-bonded C-atom is the rate-determining step. ... 

The adsorption of diphenylmercury (DPM) and phenylmercuric ion (PM) was studied on the solid phases described above (hydrous manganese oxides, amorphous iron oxides, humic acid and bentonite clay). The solid phase (5-15 mg) was added to 25-50 ml of filtered seawater yielding solid phase concentrations of approximately 100 to 400 ppm suspended matter. The concentration of seawater was also varied in order to study the variation of adsorptive behavior with changes in ionic strength. The suspension was then spiked with either DPM or PMA to yield concentrations of organometallic which varied from 0.10 to 3.5 ppm. The range in organometallic concentration used for this study was determined by the sensitivity of the detection method and the solubility of DPM and PMA in seawater. 

Djingova, R., Kostadinov, K., 1982. A method for determination of diphenylmercury in biological liquid samples. Radiochem. Radioanal. Lett. 51, 399 02. 

Baughman et al 7 studied the gas chromatographic behaviour of methylmercury compounds on a glass column (6ft x 0.25in) packed with 5% of DECS on Chromosorb W and operated at 160°C, and of phenylmercury compounds on a similar column packed with 3% of OV-1 on Chromosorb W and operated at 150 C. Flame ionization and Ni electron-capture detectors were used. Dimethyl- and diphenylmercury were stable under these conditions, but combined glc-ms confirmed that methyl- and phenylmercury salts decompose during gas chromatography. Reliable determination of methylmercury salts were achieved only on columns specially treated so as to make the decomposition reaction reproducible. Phenylmercury salts, which decompose extensively, could not be determined by gas chromatography. 

More recent work on the determination of alkylmercury compounds has been centred on the applicability of the helium microwave glow discharge detector as a gas chromatographic detector. This has been discussed by Bache and Lisk. Grossman, Talmi92 and Quimby et al have examined the applicability of helium microwave glow discharge detectors to the detection of diphenylmercury. 

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