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Gradient elution capillary electrochromatography and hyphenation with nuclear magnetic resonance
Author(s) -
Gfrörer Petra,
Schewitz Jens,
Pusecker Klaus,
Tseng LiHong,
Albert Klaus,
Bayer Ernst
Publication year - 1999
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/(sici)1522-2683(19990101)20:1<3::aid-elps3>3.0.co;2-u
Subject(s) - capillary electrochromatography , aspartame , chemistry , capillary electrophoresis , nuclear magnetic resonance spectroscopy , chromatography , elution , analytical chemistry (journal) , capillary action , gradient elution , nuclear magnetic resonance , materials science , high performance liquid chromatography , biochemistry , physics , organic chemistry , composite material
Coupling of gradient capillary electrochromatography (gradient CEC) and capillary zone electrophoresis (CZE) with nuclear magnetic resonance spectroscopy (NMR) was performed using a recently developed capillary NMR interface. This technique was applied for the analysis of pharmaceuticals and food. An analgesic was investigated using isocratic and gradient continuous‐flow CEC‐NMR. Comparison of the results demonstrated the superiority of gradient CEC over isocratic CEC. Aspartame and caffeine, both ingredients of soft beverages, were separated and analyzed by continuous flow CZE‐NMR. The order of elution could be reversed by altering the pH. This reversal led to an increased sample concentration in the NMR detection cell, thus allowing the acquisition of a totally correlated spectroscopy (TOCSY) two‐dimensional (2‐D) spectrum of the synthetic peptide aspartame.