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Simultaneous, sequential quantitative achiral–chiral analysis by two‐dimensional liquid chromatography
Author(s) -
Venkatramani Cadapakam J.,
Wigman Larry,
Mistry Kavita,
Chetwyn Nicholas
Publication year - 2012
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.201200005
Subject(s) - enantiomer , chromatography , chemistry , diastereomer , impurity , high performance liquid chromatography , phase (matter) , chiral column chromatography , chiral derivatizing agent , reversed phase chromatography , enantiomeric excess , analytical chemistry (journal) , organic chemistry , enantioselective synthesis , catalysis
In general, chromatographic analysis of chiral compounds involves a minimum of two methods; a primary achiral method for assay and impurity analysis and a secondary chiral method for assessing chiral purity. Achiral method resolves main enantiomeric pairs of component from potential impurities and degradation products and chiral method resolves enantiomeric pairs of the main component and diastereomer pairs. Reversed‐phase chromatographic methods are preferred for assay and impurity analysis (high efficiency and selectivity) whereas chiral separation is performed by reverse phase, normal phase, or polar organic mode. In this work, we have demonstrated the use of heart‐cutting ( LC – LC ) and comprehensive two‐dimensional liquid chromatography ( LC × LC ) in simultaneous, sequential achiral and chiral analysis and quantitation of minor, undesired enantiomer in the presence of major, desired enantiomer using phenylalanine as an example. The results were comparable between LC – LC and LC × LC with former offering better sensitivity and accuracy. The quantitation range was over three orders of magnitude with undesired D ‐phenylalanine detected at approximately 0.3% in the presence of predominant, desired L ‐phenylalanine (99.7%). The limit of quantitation was comparable to conventional high‐performance liquid chromatography. A reversed‐phase C 18 achiral column in the primary and reversed‐phase C hirobiotic T ag chiral column in the secondary dimension were used with a compatible mobile phase.