## 1 Introduction  
The aroma profile of wine is due to the combined effects of several volatile compounds mainly alcohols, aldehydes, esters, acids, monoterpenes and other minor components, already present in the grapes or being formed during the fermentation and maturation process. All these compounds are responsible for their so-called \"bouquet\" on sniffing the head-space from a glass, and the odour/aroma component (palate/aroma) of the overall flavour perceived on drinking [1]. Primary aromas, also known as varietal aromas, come from or are determined by the type of grapes (grape varietals) used in wine making. From the sensorial point of view they present pleasant aroma descriptors, frequently associated with flower and fruit, among others and very low odour thresholds, allowing their perception at low concentrations. Among primary aromas, a number of volatiles, which are of terpenic origin, are of great importance [2]. It has emerged from various studies that the terpenoid compounds form the axis for the sensory expression of the wine bouquet; they can be used for varietal characterisation since they are not significantly affected by the fermentation stage [3]. Monoterpenes and sesquiterpenes are the lower molecular weight representatives of the terpenoid fraction; they comprise two and three isoprene units, respectively. A general representation of the biosynthesis of monoterpenes sesquiterpenes, as well as some enzymatic transformations such as oxidation, reduction and dehydration, has been summarised by [PERSON] [4]. The monoterpenes present in wines are widely studied and the most represented are geraniol, nerol, rose oxides (floral, rose-like), linalool (coriander), linalool oxides (camphoraceous, green), nerol oxide (erbaceous) [5,6]. In Nero d'Avola wines sabinene (light, peppery, herbaceous), \(\beta\)-pinene (light, pine), limonene (green, citrus), terpinolene (fresh, pine), (E)-rose oxide (flower, geranium), (E)-linalool oxide (sweet, floral), (Z)-linalool oxide (sweet, floral), citronellal (strong, citrus green), linaly acetate (fruity, citrus), linalool (light, lavander) and neryl acetate (floral, fruity, rose) were identified [7]. However, few studies are concerning the presence of sesquiterpenoids in wine with a limited number of identified compounds. These mainly regard Madeira wines which are known to contain farnesol [8], nerolidol [8,9], \(\gamma\)-eudesmol [9], \(\alpha\)-calinol [9] and \(\tau\)-muurolol [9]. In 'Baga' wines, as well as in grapes, \(\alpha\)-muurolene, \(\alpha\)-calacorene and cadalene were identified [10]. Only a recent paper reports a large number of sesquiterpenes in Cabernet Sauvignon obtained by a comprehensive two-dimensional gas chromatography (GC\(\times\)GC) time-of-flight mass spectrometry (TOFMS) [11]. In our previous work on white Italian wines, only (E)-nerolidol was identified [1]. Sesquiterpenes have been reported as potential contributors to the health benefits of wine [10]. These compounds are described as possessing anti-inflammatory properties [12], antibacterial properties including enhancement of bacterial susceptibility to antibiotics [13], vanti-carcinogenic [14] and antioxidant effects [15]. Since the majority of these compounds occur in micro concentrations in grapes and wines, their quantification is quite difficult. The advantages and drawbacks of different extraction and gas chromatographic techniques used for the determination of sesquiterpene compounds are reviewed by [PERSON]. As results from the review quantitative data are limited [16]. Previousy it was optimized a method for the analyses of volatile constituents in wine, which allowed the identification and quantification of a large number of compounds belonged to different classes of substances [17]. The analytical approach used for the extraction of aroma volatile compounds was the solid-phase microextraction (SPME), followed by capillary gas chromatography-mass spectrometry (GC-MS). SPME-gas chromatography is routinely used for the analysis of volatile in various matrices.