A linear relationship between partition ratio and composition of a binary mobile phase in reversed‐phase liquid chromatography using chemically bonded stationary phases

Abstract

SummaryA simple linear relationship which enables the effect of the composition of a binary mobile phase on the retention of a solute to be assessed in reverse phase liquid chromatography using a bonded stationary phase has been derived. The equations have been tested using published experimental data.

Characterization of the surface composition of alkyl bonded phases under reversed-phase liquid chromatographic conditions using homologues of alkanoate and perfluoroalkanoate esters as solute probes

“…Differentiation of eq 7 with respect to nc gives the following equation (8) Equation 8 shows that the slope s from plots of In k 8 vs nc (cf. eq 7) is linearly dependent on the volume fraction " of water in the stationary phase s = a + 5 / For a series of alkyl or perfluoroalkyl homologues, s denotes the incremental change in the logarithm of the capacity ratio due to addition of a methylene or perfluoromethylene group to the alkyl chain of the solute.…”

“…In recent years, radiocarbon (14C) has become widely accepted as an atmospheric tracer of biogenic emissions and biomass combustion products (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Radiocarbon is present at known, approximately steady-state levels in all living materials.…”

“…With AMS, the measurement of 14C in various chemical fractions of interest is also possible. The method has been used to determine the fossil contribution to "organic" (i.e., volatile or oxidizable) and "elemental" (nonvolatile or nonoxidizable) carbon in atmospheric particles (9, 10), to atmospheric GH4 and CO (8,25), and to low-polarity organic compounds (LPCs) extracted from aerosols (9).…”

“…These treatments incorporate the competitive interactions that arise between the solute and solvents for the sorbent and solutesolvent and solvent-solvent interactions which arise in the mobile and surface phases. However, the resulting equations are frequently quite complicated and thus inconvenient for interpreting retention data (8). Because of such difficulties, many simpler retention models have been suggested (see reviews (1-7) and references therein).…”

“…The first case is typical for liquid-solid chromatography (i.e., polar unmodified surfaces used in the normal-phase mode (NPLC)) where the solute's distribution between the mobile and stationary phases is governed by a displacement adsorption model. The second case, is for liquid-liquid chromatography where the solute's distribution between the mobile and stationary phases is governed by a partition mechanism. In many cases in reversed-phase LC the interaction of a solute with a chemically bonded phase (RPLC-CBP) has been treated in terms of a partition model (8,20), analogous to classical partitioning of a compound between two different immiscible liquids. The distribution is determined by differences in the molecular interactions that arise in each phase.…”