Retention volume in high-pressure gas chromatography

The specific retention volume of isooctane, tetrachloromethane and toluene were measured in the Apiezon K-hydogen, nitrogen and carbon dioxide systems at temperatures of 50 and 75 C and at pressure of 10–100 atm for hydrogen and nitrogen and 10–50 atm for carbon dioxide. By comparing the results with the predictions derived from the concept of a pseudo-binary model, it was possible to assess the effect of the carrier gas dissolved in the stationary phase on the specific retention volume. The largest deviations from the pseudo-binary model were found with the isooctane-Apiezon K-carbon dioxide system.