###### Abstract  
A Stir Bar Sportive Extraction-Gas Chromatography-Mass Spectrometry (SBSE-GC-MS) method has been optimized and validated for the determination of eight volatile sulphur compounds in wine distillates: diethyl sulphide (DES), dimethyl disulphide (DMDS), diethyl disulphide (DEDS), 2-thiophenehexoladehyde (TC), dibutyl sulphide (DBS), dipropyl disulphide (DPDS), dipropyl sulphide (DPS), and dimethyl trisulphide (DMTS). After optimization by 2\({}^{4}\) factorial design, the SBSE-GC-MS extraction conditions were as follows: a polydimethylsiloxane twister (10 mm \(\times\) 0.5 mm), 35 \({}^{\circ}\)C as the extraction temperature, 10 mL as the sample volume, 7% (\(v/v\)) as the alcoholic grade, 47 min as the extraction time, 10% (\(w/v\)) of NaCl, and 1% (\(w/v\)) of EDTA (ethylenediaminetetraacetic acid). Under optimal conditions, adequate analytical figures of merit were obtained for eight of the ten compounds initially considered, with low quantification and detection limits and relative standard deviations for inter-twister and inter-day repeatability values ranging from 7.5 to 21.8% and from 7.2 to 27.5%, respectively. The methodology was applied to 34 wine distillates (continuous column distillation and distillation in pot still) elaborated for the production of Brandy de Jerez: 15 aged distillates aged for different periods of time in American oak wood and 19 non-aged distillates. The most significant volatile sulphur compounds were DBS, DMDS, and DPS. The Cluster Analysis (CA) on the volatile sulphur compounds grouped the samples according to the use of sulphur dioxide. In general, lower amounts of volatile sulphur compounds were found in the aged samples, although the high standard deviations obtained highlight that their contents depend on multiple factors related to the elaboration process. v 2025 21 March 2025 24 March 2025 2  
In the case of grape-derived beverages, these compounds are produced by two main routes: enzymatic and non-enzymatic [3]. In the enzymatic pathway, they are formed from hydrogen sulphide produced by yeasts during the winemaking process from inorganic sulphur compounds such as sulphates or sulphites, or from organic sulphur compounds such as glutathione or cysteine. The non-enzymatic pathway occurs mostly during the processing and storage stages, and involves chemical reactions catalyzed by light and/or the temperature of sulphur compounds present in the wine [4]. In distillation, being compounds with a low boiling point (below 90\({}^{\circ}\) Celsius), they pass, mainly, from the wine to the distillate in the first stage of the process (head fraction) together with other undesirable aromatic compounds. The wine distillate obtained in the central stage of the process (heart fraction) is richer in desirable aromatic compounds and has a lower concentration of VSCs [5; 6]. In addition, their concentrations may be modified during the distillation stage according to the specific conditions employed [7]. Brandy de Jerez is produced in southern Spain from wine spirits that are aged in oak wood casks for specific durations. Its volatile composition depends on the starting grape, the fermentation conditions, the conservation of the wine obtained, the distillation process, and the aging period in oak wood. Among these conditions for the fermentation and conservation of the wine until the moment of its distillation, we find the use of sulphur dioxide as a preservative, which affects both the starting wine and the distillate obtained [8]. In relation to the VSC determination, the methods of analysis of these compounds in wine distillates present certain difficulties due to factors such as the complexity of the sample matrix, the high alcohol content (over 30% alcohol by volume (ABV)), the low levels of concentration of these compounds in distilled beverages, and their high reactivity [3]. Because of this, the methods of analysis found in the literature usually present a first stage of extraction and concentration before their analysis stage by GC.