Effect of n-octanol in the mobile phase on lipophilicity determination by reversed-phase high-performance liquid chromatography on a modified silica column

Probing the coordination behavior of Hg2+, CH3Hg+, and Cd2+ towards mixtures of two biological thiols by HPLC-ICP-AES

“…After thermostating the HPLC column to 37°C, individual metals were injected onto the column and detected in the column effluent with an inductively coupled plasma atomic emission spectrometer (ICP-AES). Since the on-column formed metal-thiol complexes are expected to be retained on this C 18 -HPLC column according to their hydrophobicities [40,41], the comparative retention behavior of the investigated metal ions was intended to provide insight into their comparative coordination behavior. Thereafter, the concentration of Cys (ligand 2) in the mobile phase (5.0 mM GSH in PBS-buffer) was gradually increased from 0 to 10 mM Cys (in 0.5 or 1.0 mM steps) and each metal was again injected separately onto the HPLC-ICP-AES system.…”

Estimation of alkane–water logP for neutral, acidic, and basic compounds using an alkylated polystyrene-divinylbenzene high-performance liquid chromatography column

“…Therefore, an optimized ODS-C18 system useful for log P oct was included as a benchmark, to provide a more familiar context against which the other comparisons could be judged. The Gemini ODS-C18 column is very effective for predicting log P oct when isocratic methanol runs are extrapolated to log k w and 0.25% n-octanol is added to the mobile phase as a modifier [56]. LSER constants for this Gemini ODS-C18 system, and the  values derived from them, illustrate an HPLC system that performs well as a surrogate for partition coefficients determined via octanol-water shake-flask assays.…”

“…Using data from the literature [4,19,20,22,36,56], normalized system coefficients were calculated for other chromatography and partitioning systems and summarized (Table 2). In addition to PRP-C18, LSER analyses are reported for three other types of polymeric PS-DVB-based systems: PRP-1, Act-I, and RPS40.…”

Advances in the analysis of steroid hormone drugs in pharmaceuticals and environmental samples (2004–2010)

“…The determination of log P of steroid hormone drugs is based on its linear relationship with the CHI (Chromatography Hydrophobic Index, the percentage of the organic modifier required to obtain equal distribution of the analyte between the mobile and stationary phases) in isocratic and gradient HPLC using acetonitrile [135] or methanol [136] as the organic modifiers. The correlation for (among others) steroids could be further improved by adding 1-octanol to the mobile phase using Amide-C16 RP-HPLC [137] or C18 [138] stationary phases. The comparison of the capabilities of RP-HPLC and RP-TLC was demonstrated on the example of cortisone derivatives [139].…”