title: Optimisation of stir bar sorptive extraction applied to the determination of volatile compounds in vinegars.
abstract: Stir bar sorptive extraction (SBSE) was evaluated for analysing volatile compounds in vinegar. The extraction and desorption analytical conditions have been optimised using a two-level factorial design expanded further to a central composite design. This chemometric tool is very appropriate in screening experiments where the aim is to investigate several possibly influential and/or interacting factors. For the extraction step, the optimum analytical conditions were: sample volume 25 ml without dilution, sampling time 120 min, NaCl content 5.85 g, and stirring speed 1250 rpm. For the desorption step, the optimised analytical conditions were: desorption temperature 300 degrees C, cryofocusing temperature -140 degrees C, flow of helium 75 ml min(-1), and desorption time 10 min. The SBSE procedure developed shows detection limits, and linear ranges adequate for analysing this type of compounds. The repeatability values obtained were lower than 10%. SBSE is a very simple, solvent-free, fast technique with better sensitivities, in general, than SPME. However, a disadvantage of this technique is that, up to now, the stir bar offers a limited enrichment capability for polar compounds because is only available with PDMS coating.
authors.affiliation: Analytical Chemistry Department, Faculty of Sciences, University of Cádiz, P.O. Box 40, E-11510, Pol. Río San Pedro, Puerto Real, Cádiz, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Durán Guerrero
authors.forename: Ramón
authors.initials: R
authors.lastname: Natera Marín
authors.forename: Remedios
authors.initials: R
authors.lastname: Castro Mejías
authors.forename: Carmelo
authors.initials: C
authors.lastname: García Barroso
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014835:Volatilization
chemical_list: D019342:Acetic Acid