Robustness of an Immobilized Artificial Membrane High-Performance Liquid Chromatography Method for the Determination of Lipophilicity

Abstract

Hydrophobicity is an intrinsic property that relates to a chemical's tendency to partition between a polar and a nonpolar phase. Traditionally, hydrophobicity has been described by the logarithm of the octanol−water partition coefficient (log K OW or log P). Immobilized artificial membrane high-performance liquid chromatography (IAM-HPLC) is an alternative method to determine hydrophobicity that may be more biologically relevant. This paper examines the robustness of an IAM-HPLC assay optimized using the IAM.PC.DD2 column to determine the retention factor (log k IAM (pH 7.4) ). The method has been shown to be robust following robustness testing of five compounds (log K OW ranging from 0.29 to 6.03) assessed across five columns (which included three batches of stationary phase) and two HPLC systems.

Dealing with Confounding pH-Dependent Surface Charges in Immobilized Artificial Membrane HPLC Columns

“…Molecular structures and more detailed information are presented in the SI Table S1. 3-Nitroaniline (p K a = 2.11) was used as a neutral reference compound, following ref . Nitrate (as NaNO 3 ) and bromide (as KBr) were used as anionic tracers; thiourea and pure water, as neutral nonretaining tracers.…”

Using membrane–water partition coefficients in a critical membrane burden approach to aid the identification of neutral and ionizable chemicals that induce acute toxicity below narcosis levels

“…[43][44][45][46] The experimentally feasible range covers log D MLW 0-6, depending on detection limits for the strongest sorbing chemicals. [94][95][96] Although the silica IAM packing can have confounding coulombic electrostatic effects on the retention of anions and cations, as discussed in Section S1, † this can be corrected for by empirical or modeled Boltzmann factors. 27,48,97 Consistent IAM-based D MLW data sets have been derived for both cationic (>150 chemicals 26,77,78,98,99 ) and anionic chemicals (>20 (ref.…”