Optimisation of stir bar sorptive extraction applied to the determination of volatile compounds in vinegars

• Published in: Journal of Chromatography A 2006-02, Vol.1104 (1), p.47-53
• Main Authors: Guerrero, Enrique Durán, Marín, Ramón Natera, Mejías, Remedios Castro, Barroso, Carmelo García
• Format: Article
• Language: English
• Subjects: Acetic Acid - chemistry; Biological and medical sciences; Central composite design; Fermented food industries; Food industries; Fundamental and applied biological sciences. Psychology; Reproducibility of Results; Sensitivity and Specificity; Stir bar sorptive extraction; Two-level factorial design; Vinegar; Volatile compounds; Volatilization; Wines and vinegars
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2005.12.006

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 °C, cryofocusing temperature −140 °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.