Long-Wavelength Fluorescence Detection of Flavonoids in Orange Juices by LC

• Published in: Chromatographia Vol. 72; no. 11-12; pp. 1115 - 1120
• Main Authors: Andreu-Navarro, Alvaro, Fernández-Romero, Juan Manuel, Gómez-Hens, Agustina
• Format: Journal Article
• Language: English
• Published: Wiesbaden Wiesbaden : Vieweg Verlag 01-12-2010; Vieweg Verlag; Springer
• Subjects: Analytical Chemistry; Biological and medical sciences; Chemistry; Chemistry and Materials Science; Chromatography; Column liquid chromatography; Flavonoid compounds; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Laboratory Medicine; Long wavelength fluorescence detection; Non alcoholic beverage industries and mineral waters; Orange juice samples; Original; Pharmacy; Proteomics; Column liquid chromatography; Long wavelength fluorescence detection; Flavonoid compounds; Orange juice samples; Fluorescence detector; Chemical analysis; Aglycone; HPLC chromatography; Flavonoid; Oxazine dye; Postcolumn; Flavanone derivatives; Fluorophore; Orange juice; Flavone derivatives; Glycoside; Beverage; Quantitative analysis
• ISSN: 0009-5893; 1612-1112
• DOI: 10.1365/s10337-010-1774-8

A new post-column liquid chromatographic reaction system for the determination of flavonoids in orange juices is based on the use of the long wavelength fluorophor cresyl violet and cerium(IV) in a cetyl trimethylammonium bromide micellar medium. Two flavone aglycones (quercetin and kaempferol), a flavonone aglycone (naringenin), one flavone-O-glycoside (rutin) and two flavanone-O-glycosides (hesperidin and naringin) have been used as analyte models. The reaction process involves the interaction between the analyte, cerium(IV) and cresyl violet giving rise to a decrease in the fluorescence, measured at λ ex 585, λ em 625 nm, which is proportional to the analyte concentration. Dynamic ranges of the calibration graphs and detection limits, obtained with standard solutions of the analytes are (ng mL⁻¹): quercetin (12.2-4,000, 3.7), kaempferol (3.5-1,000, 1.0), naringenin (6.7-1,000, 2.0), rutin (5.0-800, 1.5), hesperidin (10.1-1,000, 3.0), and naringin (17.8-800, 1.8). The determination coefficients were higher than 0.993 in all instances. The precision of the method, expressed as RSD%, was established at two concentration levels, with values ranging between 2.8 and 6.2%. The practical usefulness of the developed method is demonstrated by the analysis of natural and commercial orange juices, which were filtered, diluted and directly injected into the chromatographic system, with apparent recoveries between 86.9 and 107.0%.