title: A new solid phase extraction for the determination of anthocyanins in grapes.
abstract: A method for the concentration and cleaning of red grape extracts prior to the determination of anthocyanins by UPLC-DAD has been developed. This method is of special interest in the determination of phenolic maturity as it allows the analysis of the anthocyanins present in grapes. Several different SPE cartridges were assessed, including both C-18- and vinylbenzene-based cartridges. C-18-based cartridges presented a very low retention for the glucosylated anthocyanidins while vinylbenzene-based cartridges showed excellent retention for these compounds. The optimized method involves the initial conditioning of the cartridge using 10 mL of methanol and 10 mL of water, followed by loading of up to 100 mL of red grape extract. Ten mL of water was used in the washing step and anthocyanins were subsequently eluted using 1.5 mL of acidified methanol at pH 2. This method simplifies the determination of individual anthocyanins as, on the one hand, it cleans the sample of interference and, on the other hand, it increases the concentration to up to 25:1.5. The developed method has been validated with a range of different grapes and it has also been tested as a means of determining the different anthocyanins in grapes with different levels of maturity.
authors.affiliation: Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain. jesus.ayuso@uca.es.
authors.forename: Marta
authors.initials: M
authors.lastname: Ferreiro-González
authors.affiliation: Andalusian Center for Wine Research, University of Cadiz, Puerto Real 11510, Spain. ceferino.carrera@uca.es.
authors.forename: Ceferino
authors.initials: C
authors.lastname: Carrera
authors.affiliation: Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain. ceferino.carrera@uca.es.
authors.forename: Ana
authors.initials: A
authors.lastname: Ruiz-Rodríguez
authors.affiliation: Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain. ceferino.carrera@uca.es.
authors.forename: Gerardo F
authors.initials: GF
authors.lastname: Barbero
authors.affiliation: Department of Physical Chemistry, University of Cadiz, Puerto Real 11510, Spain. jesus.ayuso@uca.es.
authors.forename: Jesús
authors.initials: J
authors.lastname: Ayuso
authors.affiliation: Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain. miguel.palma@uca.es.
authors.forename: Miguel
authors.initials: M
authors.lastname: Palma
authors.affiliation: Department of Analytical Chemistry, University of Cadiz, Puerto Real 11510, Spain. ceferino.carrera@uca.es.
authors.forename: Carmelo G
authors.initials: CG
authors.lastname: Barroso
mesh_terms: D000872:Anthocyanins / Q000737:chemistry / Q000302:isolation & purification*; D000432:Methanol / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D012997:Solvents / Q000737:chemistry; D027843:Vitis / Q000737:chemistry*
chemical_list: D000872:Anthocyanins; D010936:Plant Extracts; D012997:Solvents; D000432:Methanol