Novel zwitterionic polyphosphorylcholine monolithic column for hydrophilic interaction chromatography.
A novel porous zwitterionic monolith was prepared by thermal co-polymerisation of 2-methacryloyloxyethyl phosphorylcholine (MPC) and ethylene glycol dimethacrylate (EDMA) within 100 microm I.D. capillaries. Mercury intrusion porosimetry, scanning electron microscopy (SEM), micro-HPLC (micro-HPLC), elemental analysis and zeta-potential analysis were used to evaluate the monolithic structure. No evidence of swelling or shrinking of the monolith in different polarity solvents was observed. A typical hydrophilic liquid chromatography (HILIC) mechanism was observed at high organic solvent content (acetonitrile >60%). The phosphorylcholine (PC) functionality has both a positively charged quaternary ammonium and a negatively charged phosphate group. For charged analytes, a weak electrostatic interaction was also observed by studying the influence of mobile phase pH and salt concentration on their retentions on the poly(MPC-co-EDMA) monolithic column. The optimised poly(MPC-co-EDMA) monolith showed very good selectivities for a range of polar test analytes, especially small peptides. This might be ascribed to the good biocompatibility of PC functionality. At low organic solvent content, baseline separation was also observed for a test mixture of seven alkylphenones by a reversed-phase separation mechanism.
Jiang
Zhengjin
Z
Novartis Institutes for Biomedical Research, Global Discovery Chemistry, Horsham, UK. zhengjin.jiang@novartis.com
Reilly
John
J
Everatt
Brian
B
Smith
Norman W
NW
D002853:Chromatography, Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007659:Ketones / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D010455:Peptides / Q000032:analysis; D010539:Permeability; D010767:Phosphorylcholine / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D011687:Purines / Q000032:analysis; D011743:Pyrimidines / Q000032:analysis; D015203:Reproducibility of Results; D012492:Salts / Q000737:chemistry; D012680:Sensitivity and Specificity; D012997:Solvents / Q000737:chemistry; D055672:Static Electricity
D007659:Ketones; D010455:Peptides; D011108:Polymers; D011687:Purines; D011743:Pyrimidines; D012492:Salts; D012997:Solvents; D010767:Phosphorylcholine