Generalized equations to evaluate the gas hold-up time of chromatographic systems

Summary The two approaches used for the calculation of the gas hold-up time and thus, the adjusted retention time are outlined, first for the restricted case when the carbon numbers of the three homologues used for the calculation are evenly spaced (c₃–c₂=c₂–c₁) and then, for the general case when (c₃–c₂) differs from (c₂–c₁). The basic difference in the philosophy of the two approaches is shown.