Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

Partitioning coefficients of 44 organic solutes between hexadecan-1-ol and the gas phase at temperatures between 333.15 K and 383.15 K were determined with the phase ratio variation (PRV) method based on headspace gas chromatography. It was first established that the PRV method is suitable to determine partition coefficients using a solid matrix containing multiple solutes. Hexadecane/air partition coefficients for nonane and octan-1-ol measured using the PRV method agreed well with data from the literature. Homogeneous solutions of solid hexadecano- 1-ol were prepared through melting, quick re-coagulation, and grinding. Exact phase ratios were determined by measuring mass and density. Comparison of partition coefficients determined using solutions containing either a single or multiple solutes showed that, in dilute solutions, the impact of the other solutes on the partitioning behavior can be neglected. Using very large phase ratios, the upper limit of partition coefficients that can be measured by the PRV method could be extended to approximately 20 000. The hexadecan-1-ol/air partition coefficients extrapolated to 298.15 K were well-correlated with both liquid-state vapor pressure and the octan- 1-ol/air partition coefficient, suggesting that the partitioning behavior of most organic solutes in aliphatic alcohols can be estimated from their vapor pressure with a precision of approximately 1 order of magnitude simply by assuming that the activity coefficient is 1. The free energies, enthalpies, and entropies of hexadecan-1-ol/air phase transfer were derived from the measured data, and the phase transfer enthalpy was found to be correlated with the partition coefficient at 298.15 K.