Retention corrected,definition

In gas chromatography the analyte partitioning between mobile gas phase and stationary liquid phase is a real retention mechanism also, phase parameters, such as volume, thickness, internal diameter, and so on, are well known and easily determined. In liquid chromatography, however, the correct definition of the mobile-phase volume has been a subject of continuous debate in the last 30 years [13-16]. The assumption that the retardation factor, i /, which is a quantitative ratio, could be considered as the fraction of time that components spend in the mobile phase is not obvious either. 

Solvent interaction model for normal-phase liquid chromatography. The solvent-interaction model of Scott and co-workers (Scott and Kucera, 1979) assumes that the analyte partitions between the bulk mobile phase and a layer of solvent absorbed onto the stationary phase. The quantitative description of the relationship between retention and the composition of the mobile phase in the solvent-interaction model requires the definition of the void volume corrected retention volume (V), which is related to the retention volume (F ) and the void volume (Fq) by... 

Because the definition of the adjusted retention volume was given above, and a related definition of the corrected retention volume was given in Chapter 2 (equation 4), we ought to make sure that these two are not confused with one another. Each has its own particular definition the adjusted retention volume, Fr is the retention volume excluding the void volume (measured from the methane or air peak) as shown in equation 9 the corrected retention volume, Vg, is the value correcting for the compres-... 

The easily accepted n-alkanes (n-C H2n+2), with postulated R1 values RI = 100 x c [e.g., methane (CH4)—100, n-non-ane (C9H20)— 900, n-hentriacontane (CsiHsa)—3100, etc.], were recommended as reference compounds. This is because, under isothermal conditions of GC analysis, a linear dependence of logarithms of corrected retention times Jr = r - fo ( o is the hold up time of chromatographic system) on the number of carbon atoms in the molecule of homolog is observed, i.e., log r = anc + b. Keeping in mind that (by definition) lOOnc = the existence of the following linear dependence is implied ... 

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