Biomembrane lipids as components of chromatographic phases: Comparative chromatography on coated and bonded phases

Preparation of biomembrane lipid based stationary phases has been achieved by recycling 1 mM solutions of the appropriate lipid (soybean lecithin phosphatidylcholine, SLPC; phosphatidylcholine, sphingomyelin, phosphatidylethanolamine or phosphatidylserine) in methanol: water (80:20 v/v) through reversed-phase (C8) HPLC columns for 18 hours at 0.25 mL min^-1. The chromatographic characteristics (retention, peak symmetry and reproducibility and phase stability) have been assessed and compared with two commercially available bonded Immobilized Artificial Membrane (IAM) phases (IAM.PC.MG and IAM.PC.DD) by examination of the retention properties of a range of structurally diverse analytes (n = 119). The application of the SLPC phase for prediction of analyte lipophilicity (log Poctanol/water) is shown to be comparable to the IAM.PC.MG and superior to the IAM.PC.DD bonded phases. Cross-phase comparison of analyte retention characteristics on four different lipid phases indicate that such phases may provide a rapid evaluation of analyte-lipid interactions. The dynamic coating methodology is economically viable for the small laboratory, rapid and reproducible, resulting in phase surfaces which are stable over longer periods of time than those of the commercially available bonded phases.