title: Molecular species analysis of phosphatidylcholine by reversed-phase ion-pair high-performance liquid chromatography.
abstract: The retention behavior of molecular species of phosphatidylcholine (PC) is studied by reversed-phase (RP) ion-pair high-performance liquid chromatography (HPLC). Mobile phases contain tetraalkyl ammonium phosphates (TAAPs) in methano-acetonitrile-water. The stationary phase is alkyl-bonded silica. Competitive interactions of TAAPs, analyte solutes, and an RP-HPLC column result in reduced retention of PC molecular species. PC molecular species are eluted at longer retention times with a larger size of TAAP in the mobile phase, and an increase in the TAAP concentration invariably causes a decrease in PC molecular species retention times. There is a linear correlation between the logarithmic retention factors (k) of PC molecular species and the total number of carbon atoms of TAAP, and the logarithm of k values of PC molecular species can be approximated as a linear function of the logarithm of the counter-ion concentration. There is found to be no distinct dependence between k values of PC molecular species and the mobile phase pH.
authors.affiliation: Antigen Express, Inc., 100 Barber Avenue, Worcester, MA 01606, USA. xueqing_lu@yahoo.com
authors.forename: Xueqing
authors.initials: X
authors.lastname: Lu
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiaokun
authors.initials: X
authors.lastname: Hong
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010713:Phosphatidylcholines / Q000737:chemistry*
chemical_list: D010713:Phosphatidylcholines