title: High-performance liquid chromatographic analysis of phlorotannins from the brown alga Fucus vesiculosus.
abstract: Separating individual compounds by HPLC represents an effective method for the detection and quantification of phenolic compounds and has been widely utilised. However, phlorotannins are commonly quantified using colorimetric methods, as the total amount of the whole compound group. In the present paper the separation of a set of individual soluble phlorotannins from the phenolic crude extract of Fucus vesiculosus was achieved by HPLC with UV photodiode array detection. Different gradient programs for reversed- and normal-phase HPLC methods were developed and tested. Normal-phase (NP) conditions with a silica stationary phase and a mobile phase with a linear gradient of increasing polarity were found to separate 16 individual components of the phenolic extract. The suitability of the NP-HPLC method for mass spectrometric application was preliminarily tested. Sample preparation was found to be a critical step in the analysis owing to the rapid oxidation of phlorotannins; ascorbic acid was used as an antioxidant.
authors.affiliation: The Laboratory of Organic Chemistry and Chemical Biology, Department of Chemistry, University of Turku, FIN 20014 Turku, Finland. riitta.koivikko@utu.fi
authors.forename: Riitta
authors.initials: R
authors.lastname: Koivikko
authors.forename: Jyrki
authors.initials: J
authors.lastname: Loponen
authors.forename: Kalevi
authors.initials: K
authors.lastname: Pihlaja
authors.forename: Veijo
authors.initials: V
authors.lastname: Jormalainen
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D044645:Fucus / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry; D013634:Tannins / Q000032:analysis* / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D013634:Tannins