Headspace solid phase microextraction (SPME) analysis of flavor compounds in wines. Effect of the matrix volatile composition in the relative response factors in a wine model

The application of headspace solid phase microextraction (SPME) for flavor analysis has been studied. Headspace SPME sampling was tested for nine comm on wine flavor compounds in 10% (v/v) aqueous ethanol: linalool, nerol, ger aniol, 3-methyl-1-butanol, hexanol, 2-phenylethanol, ethyl hexanoate, ethyl octanoate, and ethyl decanoate. The chemical groups (monoterpenoids, aliph atic and aromatic alcohols, and esters) showed specific behavior in SPME an alysis. SPME sampling parameters were optimized for these components. Relat ive response factors (RRFs), which establish the relationship between the c oncentration of the compound in the matrix liquid solution and the GC peak area, were estimated for all compounds. Log(10)(RRF) varied from 0 (3-methy l-1-butanol) to 3 (ethyl decanoate), according to their molecular weight. Q uantification by SPME was shown to be highly dependent on the matrix compos ition; the compounds with higher RRF were the less affected. As a consequen ce, the data obtained with this methodology should be used taking into cons ideration these limitations, as shown in the analysis of four monovarietal Bairrada white wines (Arinto, Bical, Cerceal, and Maria Gomes).