Open AccessPeak Parking-Moment Analysis Method for the Measurement of Surface Diffusion Coefficients
Author(s) -
Kanji Miyabe,
Yuko Matsumoto,
Nobuho Ando
Publication year - 2009
Publication title -
analytical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 73
eISSN - 1348-2246
pISSN - 0910-6340
DOI - 10.2116/analsci.25.211
Subject(s) - chemistry , diffusion , solvation , analytical chemistry (journal) , enthalpy , phase (matter) , molecular diffusion , surface diffusion , aqueous solution , solvent , chromatography , thermodynamics , organic chemistry , adsorption , physics , metric (unit) , operations management , economics
The peak parking (PP)-moment analysis (MA) method was applied to the measurement of surface diffusion coefficients (D(s)) in reversed-phase liquid chromatography using a C(18)-silica gel and an aqueous solution of methanol (70 vol%). The values of D(s) measured by the PP-MA method were in agreement with those obtained by the pulse response (PR)-MA method, which is one of powerful strategies for the quantitative study on the mass transfer kinetics in columns and stationary phases. It was demonstrated that the PP-MA method is an alternative for the experimental measurement of D(s). The mechanism of surface diffusion was considered on the basis of molecular diffusion by introducing a restriction energy (E(r)) for surface diffusion. Physical meanings of E(r) were discussed by analyzing the correlation between the enthalpy change due to sample retention (Q(st)) and D(s). It seems that surface diffusion of a sample molecule is restricted by its retention strength and by the solvent structure formation due to the hydrophobic solvation of the stationary phase surface.