COMPARATIVE ADSORPTION STUDY OF DODECANOL AND CHOLESTEROL FROM ETHYLENE-GLYCOL ON THE MERCURY-ELECTRODE AND AIR SOLUTION INTERFACE/

The results of an adsorption study of dodecanol and cholesterol at the Hg/ethylene glycol solution interface and at the free surface of ethy lene glycol are presented. The significant differences in the adsorpti on behaviour of these two compounds are discussed comparing the values of the adsorption parameters (standard Gibbs energy, interaction para meter and maximum surface concentration) obtained by fitting the exper imental points to the Frumkin isotherm. In the case of cholesterol the standard Gibbs energy, Delta G(d)egrees, is markedly greater for adso rption on the mercury than at the free surface. In the case of dodecan ol, the difference in Delta G(d)egrees values at both interfaces is in significant. The plausible surface orientations of these two substance s at both interfaces are discussed.