Solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC–MS) determination of volatile compounds in orujo spirits: Multivariate chemometric characterisation

A headspace solid-phase microextraction gas chromatography mass spectrometric procedure (HS-SPME-GC–MS) was developed and applied in order to determine 22 volatile compounds (including alcohols, esters, aldehydes and terpenes) in different orujo spirit samples from the Geographic Denomination “Orujo de Galicia/Augardente de Galicia”. The orujo samples considered in this study were elaborated from Albariño variety grapes grown in the Rías Baixas restricted geographical area, and Albariño variety grapes grown in other geographical areas of Galicia (NW Spain) using two of the traditional distillation techniques: alembic and steam distillation. HS-SPME adequate results were obtained using a 65 μm carbowax-divinylbencene fibre during a headspace extraction at 40 °C with constant magnetic stirring for 15 min, and after a 5 min period of pre-equilibrium time. Desorption was performed directly in the gas chromatograph injector port for 5 min at 250 °C using the splitless mode. The applied method was demonstrated to be sensible, accurate, precise, and linear over more than one order of magnitude. Multivariate chemometric techniques (such as cluster analysis, principal component analysis and linear discriminant analysis) were used to characterise the orujo samples according to the geographical origin of the grapes and the distillation system employed in their elaboration on the basis of the chemical information provided for their volatile composition data.