title: Hollow fibre liquid phase micro-extraction by facilitated anionic exchange for the determination of flavonoids in faba beans (Vicia faba L.).
abstract: BACKGROUND
  Flavonoids are polyphenolic compounds found ubiquitously in foods of plant origin. They are commonly extracted from plant materials with ethanol, methanol, water, their combination or even with acidified extracting solutions. The disadvantages of these methods are the use of high quantity of organic solvent, the possible loss of analytes in the different steps and the laborious process of the techniques. In addition, the complexity of the phenolic mixtures present in plant materials requires a preliminary clean-up and fractionation of the crude extracts.
  
  
  OBJECTIVE
  To develop a hollow fibre liquid phase micro-extraction (HF-LPME) method for a one step clean-up and pre-concentration of flavonoids.
  
  
  METHODS
  Two flavonoids (catechin and rutin) has been extracted by HF-LPME and analysed by HPLC. The related driving force for the liquid membrane has been studied by means of facilitated and non-facilitated transport. Different ionic and non-ionic water insoluble compounds [trioctylamine (TOA), tributyl phosphate (TBP), trioctylphosphine oxide (TOPO) and methyltrioctylammonium chloride (aliquat 336)] were used as carriers. The liquid membrane was constituted by a solution of n-decanol in the presence or absence of carriers.
  
  
  RESULTS
  Maximum enrichment factors were obtained with n-decanol/aliquat 336 (20%) as organic liquid membrane, sodium hydroxide (NaOH) (0.1 M) as donor solution, sodium chloride (NaCl) (2 M) as acceptor solution and 3 h as extraction time. Under these conditions, good results for validation parameters were obtained [for linearity, limit of detection (LOD), limit of quantitation (LOQ) and repeatability].
  
  
  CONCLUSIONS
  The developed method is simple, effective and has been successfully applied to determine catechin and rutin in ethanolic extracts of faba beans.
authors.affiliation: Centre Grup de Tècniques de Separació en Química (GTS), Química Analítica, Departament de Química, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.|Department of Horticultural Sciences, Agro-Biodiversity Unit, Higher Agronomic Institute (ISA), University of Sousse-IRESA, Chott-Mariem, 4042, Sousse, Tunisia.|Regional Office of Agriculture Development Research Semi Arid North West, B.P. 221-7100, Le Kef, Tunisia.
authors.forename: Nadia
authors.initials: N
authors.lastname: Chaieb
authors.affiliation: Centre Grup de Tècniques de Separació en Química (GTS), Química Analítica, Departament de Química, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: López-Mesas
authors.affiliation: Centre Grup de Tècniques de Separació en Química (GTS), Química Analítica, Departament de Química, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
authors.forename: Johannes
authors.initials: J
authors.lastname: Luis González
authors.affiliation: Department of Horticultural Sciences, Agro-Biodiversity Unit, Higher Agronomic Institute (ISA), University of Sousse-IRESA, Chott-Mariem, 4042, Sousse, Tunisia.
authors.forename: Messaoud
authors.initials: M
authors.lastname: Mars
authors.affiliation: Centre Grup de Tècniques de Separació en Química (GTS), Química Analítica, Departament de Química, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Valiente
mesh_terms: D000838:Anions / Q000737:chemistry; D002392:Catechin / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D000431:Ethanol / Q000737:chemistry; D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D059627:Liquid Phase Microextraction / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012431:Rutin / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry; D031307:Vicia faba / Q000737:chemistry*
chemical_list: D000838:Anions; D005419:Flavonoids; D012997:Solvents; D000431:Ethanol; D012431:Rutin; D002392:Catechin
keywords: Hollow fibre liquid phase micro-extraction; catechin; faba bean; facilitated anionic exchange; flavonoids; rutin