Dependence of the relative retention of compounds on the average pressure of helium as a carrier gas in capillary GLC

Abstract

The dependence of retention factorki, relative retention time αi, and retention indexIi of organic compounds on the average pressure (pav) of the carrier gas (helium) was studied experimentally using a long narrow-bore capillary column with the SE-30 nonpolar phase at 120°C. The linear dependenceski=f(pav), αi=φ(pav), andIi=φ(pav) obtained previously were found to be in good agreement with experimental data. Invariant relative retention valuesk0,i, α0,i, andI0,i, which do not depend on the helium pressure, were determined for some organic compounds of various chemical classes. The dependence of the relative retention on the carrier gas pressure needs to be taken into account in precision measurements and in experiments with narrow-bore capillary columns.