Ep. Promyshlennikova et al., VARIATION IN THE SORPTION ENERGY OF ESTERS OF N-PERFLUOROALKANOIC ACIDS ON CHROMATOGRAPHIC PHASES OF DIFFERENT POLARITY, Russian chemical bulletin, 42(12), 1993, pp. 1963-1967
The contributions of methylene and difluoromethylene units of six homo
logous and six pseudohomologous series of esters of n-perfluoroalkanoi
c acids to the differential molar free energy, enthalpy, and entropy o
f sorption on stationary phases of different polarities in glass capil
lary columns under isothermal conditions were calculated. The features
observed characterize the peculiarities of the sorption of esters of
polyfluorinated carboxylic acids on phases of different polarities and
make it possible to estimate the enthalpy and entropy contributions t
o the energy of sorption of the esters, the effect of the temperature
of the analysis and the length of the alkyl or polyfluoroalkyl chain o
n the retention parameters of the compound analyzed. The inversion of
the retention order of trifluoroacetates and pentafluoropropionates in
XE-60 nitrile-containing phase was found.