Rapid Analysis of Theaflavins by High Performance Liquid Chromatography / Atmospheric Pressure Chemical Ionization-Mass Spectrometry
Chung-Wen Chen,Yi-Wei Chang and Lucy Sun Hwang*
Graduate Institute of Food Science and Technology, National Taiwan University, 59 Lane 144, Keelung Road Sec. 4, Taipei , Taiwan, ROC
ABSTRACT
A 10 cm x 4.6mm i.d. SilicaROD RP-18 HPLC column coupled with isocratic elution with a solvent system of acetonitrile-2% acetic acid or acetonitrile-1% citric acid were used to analyze purchased theaflavin mixtures and theaflavin extracts from black tea. Individual theaflavins were well separated and the analysis of theaflavins was achieved in 10 min using this method. HPLC coupled with Atmospheric Pressure Chemical Ionization-Mass Spectrometry (APCI-MS) in the positive ion mode was used to identify individual theaflavins. Quasi-molecular ions and many structural characteristic fragment ions were observed in the mass spectra. Possible fragmentation pathways from the protonated theaflavins were also proposed.
Key words :theaflavins, Atmospheric Pressure Chemical Ionization, APCI, liquid chromatography / mass spectrometry, LC/MS