Linear dependence of retention factor of compounds chromatographed on average column pressure in capillary gas-solid chromatography

The dependence of the retention factor of compounds on the average pressure was theoretically considered for binary gas mixture on the basis of a new form of Langmuir adsorption equation taking into consideration the substitu tion reaction of the adsorbed molecule of the carrier gas for the adsorbed molecule of compound chromatographed. The retention factor is linearly depe ndent on the average carrier gas pressure. The equation suggested conformed well with experimental data for different adsorbents. The influence of the gas phase processes on the retention dependence of the nature and pressure of the carrier gas can be neglected. But the carrier gas influence on the retention is pronounced. The variation in the retention factor when changin g one carrier gas for another ranges up to 30%. (C) 1999 John Wiley & Sons, Inc.