Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Proceedings
Publication Acceptance Date: 12/20/2002
Publication Date: 12/31/2002
Citation: MANTHEY, J.A. ANALYSIS OF FLAVONOIDS AND HYROXYCINNAMATES IN CITRUS PROCESSING BYPRODUCTS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY-ELECTROSPRAY IONIZATION-MASS SPECTROMETRY. PROCEEDINGS OF FLORIDA STATE HORTICULTURAL SOCIETY. 2002. v. 115. p. 292-297. Interpretive Summary: Improved analytical methods to study a specific class of compounds, termed flavonoids, in citrus peel were developed. These analytical methods involve new instrumentation that measure the molecular weights of individual compounds in citrus. This instrumentation, termed HPLC-MS, vastly improves the sensitivity of detection of many of these compounds. This instrumentation allows the detection of extremely trace quantities of the flavonoids, and provide a powerful means of confirming the identities of these compounds. HPLC-MS represents an important improvement in studying the flavonoids in citrus.
Technical Abstract: Electrospray ionization-high performance liquid chromatography-mass spectrometry (ESI-HPLC-MS) greatly facilitates analyses of the complex phenolic constituents of citrus peel and associated citrus processing byproducts. The numerous flavonoid glycosides and polymethoxylated flavones (PMFs) in these materials can be readily detected by positive ion ESI mode. Single ion monitoring (SIM) mode allows for selective detection and enhanced quantitation of the PMFs and other flavonoid glycosides in spite of incomplete chromatographic peak separations. Flavonoid-O-glycosides fragment with source cone voltages in ways that confirm structural assignments. These fragmentation patterns allow for the detection of other trace-occurring chemical species with specific flavonoid components. Many of the hydroxycinnamates are best detected by the ESI negative ion mode. However, the fragmentation patterns obtained with positive ESI allow structural information to be obtained for individual components of this complex group of compounds.