## 1 Introduction  
Monoterpene compounds are known to be important aroma compounds in aromatic white wines [1; 2; 3]. While it is noted that monoterenes are important to aromatic white wine varieties, enantiomers of monoterpene compounds have been little explored in wine. Enantiomers are chiral molecules that are non-superimposable mirror images of each other. Many molecules are enantiomers, with one enantiomer being \"active\" and the other \"inactive\" such as with many pharmaceuticals. In wine, enantiomers of volatile aroma compounds have been found to have different perception thresholds and aroma descriptions [4]. For instance, (R)-(+)-limonene has a perception threshold of 200 ppb and an aroma of fresh, citrus and orange-like, while (S)-(-)-limonene has a perception threshold of 500 ppb and aroma described as harsh, turpentine-like, lemon note [5]. In nature many chiral compounds are enantio-pure or only found in one form. Unlike many other wine aroma compounds, terpen are primarily derived from grapes, a natural source. These terpen are present in bound forms in the grape (known as glycosides, as they are bound to sugars) and are not aromatically active. Once the terpen are unbound, or free, they contribute to aroma [6]. There are some free forms in grapes but much of the free terpene content of wine is released during fermentation [6]. The free forms are released from their sugars due to enzymes, typically found in the yeast. However there are enzyme treatments (using glycosidase enzymes) that can increase the free terpene content of wine. Therefore the chiral terpene content of wine may be due to either viticulture or winemaking processes. It is entirely possible that these chiral compounds may be enantio-pure in wine or be present in all or some of their enantiomers. Due to their various properties and content in wine, the concentration of enantiomers or enantiomer excess has potential to explain relationships between wine chemistry, wine sensory, place of origin or different viticultural or winemaking processes that have been problematic or less explored in the past. While the properties of chiral compound in wine are known, and mentioned above, measurement of the different enantiomers is challenging. The first record of enantiomeric separation in wine dates back to the mid 1800s with [PERSON]'s separation of tartaric acid enantiomers [7; 8; 9]. Since this achievement chemists have looked for improved methods for the analysis and separation of chiral compounds. Derivatization of analytes with chiral reagents to form diastereomers and then chromatographically separated on achiral phases has been widely employed [10]. However this method has not been found to be successful for a range of chiral compounds, specifically chiral volatile aroma compounds. Direct separation of enantiomeric compounds on chiral amide-based GC stationary phase (e.g., Chirasil-val) was demonstrated in the mid 1960s [11; 12]. These columns allowed for excellent separation of amino acids but had limited application for analysis of most volatile compounds. With the introduction of chiral cyclodextrin-based GC stationary phases in the late 1970s and 1980s, chemists were provided with the ability to directly separate a large number of undertivatized chiral compounds [13]. For example, several early studies demonstrated separations of cyclic and acyclic enantiomers with a range of functional groups including lactones, terpene hydrocarbons, carbonyls, alcohols, spiroketals, and oxiranes [14; 15; 16]. For the analysis of grapes and wines, cyclodextrin stationary phases have been used to establish the enantiomeric distribution of isomeric 3,4-dihydro-3-oxoedulans in Riesling wine [17], and solerone (5-oxo-4-hexanolide) and Riesling acetal (2,2,6,8-tetramethyl-7,11-dioxatricyclo[6.2.1.01,6]undec-4 ene) in brandy and Riesling [18].