A chemical catalytic method for determination of silver in human saliva.
Abstract A catalytic method for the determination of silver in saliva is suggested. Silver was determined by a very simple technique in concentrations in saliva higher than 1 μg/100 ml with a coefficient of variation of 5.7 per cent. The method was used to investigate the correlation between some pathogalvanic phenomena connected with the presence of amalgam restorations in the oral cavity and the concentration of silver in saliva. The application of the method showed no correlation between the number of restorations and the silver concentration in saliva. The joint effects of restorations, their corrosion potential and the concentration of silver in saliva were correlated with the occurrence of unpleasant sensations in the mouth.
Mechanism of silver(I) catalysed sulphanilic acid oxidation by persulphate
The mechanism of sulphanilic acid oxidation with persulphate catalysed by silver(I) is reported. The first rate-limiting step of the process is a second-order reaction giving the active intermediates Ag(II) and SO4− which further oxidize sulphanilic acid. The uncatalysed reaction proceeds in a similar way with a second order interaction between the substrate and the oxidant. It is supposed that the second-order reactions of persulphate with the substrate (the uncatalysed reaction) or with the catalyst (the catalytic reaction) are processes of nucleophilic substitution on oxygen.
Wirkung der Sulfosäuregruppe auf aromatische Systeme: Hammett's σ‐Werte des SO3−‐Substituenten
1. Acidity constants of the m- and p- sulphonic acid ions of phenol, benzoic acid and anilinium ion were measured in water at different ionic strengths by the potentiometric and the spectrophotometric method.