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Effect of the residual silanol group protection on the liquid chromatographic resolution of α‐amino acids and proton pump inhibitors on a ligand exchange chiral stationary phase
Author(s) -
Ma Dong Hee,
Jin Jong Sung,
Jeong Euh Duck,
Hyun Myung Ho
Publication year - 2013
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201300079
Subject(s) - silanol , chemistry , enantiomer , lansoprazole , resolution (logic) , ligand (biochemistry) , chiral ligand , rabeprazole , chromatography , pantoprazole , lipophilicity , organic chemistry , enantioselective synthesis , omeprazole , catalysis , proton pump inhibitor , medicine , biochemistry , receptor , artificial intelligence , computer science
A new ligand exchange chiral stationary phase (new CSP ) containing residual silanol group‐protecting n ‐octyl groups on the silica surface was prepared by treating a ligand exchange CSP (original CSP ) based on sodium N ‐[( R )‐2‐hydroxy‐1‐phenylethyl]‐ N ‐undecylaminoacetate bonded to silica gel with excess n ‐octyltriethoxysilane. The new and original CSP s containing an identical amount of chiral selector were applied to the resolution of α‐amino acids and proton pump inhibitors ( PPI s) including omeprazole, pantoprazole, lansoprazole, and rabeprazole. The separation factors (α) and resolutions ( R S ) were greater on the new CSP than on the original CSP except for the resolution of asparagine. The trends of the retention factors ( k 1 ) for the resolution of α‐amino acids on the new and original CSP s with the variation of the organic modifier content in aqueous mobile phase were opposite to those for the resolution of PPI s. Removal of the nonenantioselective interactions between the residual silanol groups and the analytes and the improved lipophilicity of the new CSP were proposed to be responsible for the improved chiral recognition ability of the new CSP and the different retention behaviors of the enantiomers between the new and original CSP s.