Hyphenated Gas Chromatography – Mass Spectrometry analysis of 3-mercaptohexan-1-ol and 3-mercaptohexyl acetate in wine. Comparison with results of other sampling procedures via a robust regression.

This work describes a new purge and trap gas chromatography electron impact mass spectrometry (PT–GC–EIMS) method for quantifying 3-mercaptohexan-1-ol (3-MH) and 3- mercaptohexyl acetate (3-MHA), two molecules able to characterize some wines with their tropical scents. Firstly the experimental conditions of the purge and trap extraction (sample temperature, extraction time, trap temperature, flowrate) following amultivariate approach were optimized. Then the method through the construction of the calibration curves and the establishment of the detection limits was validated. The purge and trap procedure appears faster and more sensitive than both the headspace solid phase microextraction (HS-SPME) and the solid phase extraction (SPE) procedures, reaching detection limits for the two thiols closer to their sensory thresholds. Evidence of similar performances of the three sampling methods considered was gained comparing the results relevant to same wine samples. The Theil’s regression method was used for purpose of comparison.