Adsorption of flavonoids on resins: hesperidin.
Adsorption of hesperidin from aqueous solutions on styrene-divinylbenzene (SDVB) and acrylic resins was investigated at different pH values (1.5-5.5) and temperatures (10-40 degrees C). Adsorption was not affected by pH variation, whereas it increased on increasing temperature for the SDVB resins and remained substantially unchanged for the acrylic ones. The different behavior of the two types of resins was ascribed to the different wetting, because of their hydrophobic or partially hydrophilic properties, respectively. The equilibrium data at 20 degrees C were determined on 13 commercial resins displaying a wide range of surface areas (S(A), 330-1200 m(2)/g) and pore radii (P(R), 20-260 A). Data were well fitted to the Freundlich isotherm, and its parameters were used to compare the adsorption capacity of different resins. The most effective resin is a SDVB copolymer with the largest S(A) (1200 m(2)/g) and an intermediate P(R) (90 A). The Freundlich constants (K(F)) were rationalized in terms of a two parameter equation, including S(A) and P(R) as independent variables. The adsorption constant increased on increasing both S(A) and P(R) for the resins having P(R) </= 90 A; beyond this limit, the contribution of S(A) was predominant and that of P(R) was slightly negative.
Scordino
Monica
M
Dipartimento di OrtoFloroArboricoltura e Tecnologie Agroalimentari, Sezione Tecnologie Agroalimentari, Università degli Studi di Catania, Via S. Sofia 98, 95123 Catania, Italy.
Di Mauro
Alfio
A
Passerini
Amedeo
A
Maccarone
Emanuele
E
D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005419:Flavonoids / Q000737:chemistry*; D006569:Hesperidin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D020058:Styrene / Q000737:chemistry; D013696:Temperature; D014753:Vinyl Compounds / Q000737:chemistry
D000180:Acrylic Resins; D005419:Flavonoids; D014753:Vinyl Compounds; D020058:Styrene; D006569:Hesperidin; C004985:divinyl benzene