ISSN:
0021-8383
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The polarographic behaviour of thio-salicylic acid (TSH) at d.m.e. has been investigated in the presence of KNO3 in the pH range 1.60 to 13.50 at 30.0 ± 0.2°C in 40% ethanol (by volume) at 0.2 M ionic strength. Well defined anodic waves were obtained at all pH values. The effect of pH, concentration of TSH, drop time, temperature and ethanol, on the wave characteristics and the mechanism of the reaction at the surface of mercury drop have been studied in detail. The reversibility of the reaction mechanism was confirmed by a number of methods. The wave was diffusion controlled, reversible involving one electron transfer process and proportional to TSH concentration. Methematical and experimental evidence shows that the anodic wave of TSH at d.m.e. does not correspond to the formation of (TSST) but to a mercury compound, TSHg. The diffusion coefficients and temperature coefficients for the range of 20-45°C of id at pH 5.70 and 9.20 have been found to be 5.248; 5.105 × 10-6 cm2 · sec-1 and 1.215, 1.127% per degree, respectively. The dissociation constant (pK) was found to be 9.80 by the plot E1/2 vs. pH. The linearity of id with TSH concentrations provides a rapid and precise method for the determination of TSH down to 0.06 mM.
Zusätzliches Material:
5 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/prac.19743160610
Permalink
