Fragrances and products deriving from essential oils are often formulated or diluted in aqueous media, usually ethanol/water. Gas chromatography (GC) is the technique of choice to analyze volatiles. However, when using columns coated with conventional stationary phases, its application to aqueous samples often requires time-consuming and/or discriminative sample preparation techniques to extract the target analytes from the aqueous medium, so as to avoid its direct injection. In GC with conventional columns, water produces peak asymmetry, poor sensitivity and efficiency, strong adsorption, stationary phase degradation, and, last but not least, it is not easy to detect reliably when present in high amounts. In 2012, Armstrong’s group introduced new fully water-compatible ionic-liquid (IL)-based GC capillary columns based on phosphonium and imidazolium derivative cations combined with trifluoromethanesulphonate. These columns were recently made available commercially by Supelco, under the trade name Watercol™. These derivatives maintain IL’s unique selectivity and chromatographic properties, and enable water to be used as injection solvent, thus avoiding the sample preparation procedures required by conventional columns. This study reports and critically discusses the results of commercially available water-compatible IL columns for direct analysis of aqueous samples in the fragrance and essential oil fields by GC with thermal conductivity (TCD) and/or flame ionization detectors (FID). The results showed that water-compatible IL-based stationary phases can successfully be adopted for qualitative and quantitative analysis of fragrances and essential oils directly diluted in aqueous solvents. On the other hand, the study also shows that their inertness needs to be further increased and (possibly) the range of operative temperature extended when water is the main solvent of the sample.

来自香精油的香料和产品通常在水性介质（通常是乙醇/水）中配制或稀释。气相色谱（GC）是分析挥发物的首选技术。但是，当使用涂有常规固定相的色谱柱时，将其应用于水性样品通常需要耗时和/或有区别的样品制备技术，以从水性介质中萃取目标分析物，以避免直接注入。在具有常规色谱柱的GC中，水会产生峰不对称，灵敏度和效率低，吸附力强，固定相降解等问题，而且最后但并非最不重要的一点是，当大量存在时，不易可靠地检测到。在2012年，阿姆斯特朗（Armstrong）小组引入了基于new和咪唑鎓衍生物阳离子与三氟甲磺酸盐结合的新型完全水相容性基于离子液体（IL）的气相色谱毛细管柱。这些色谱柱最近由Supelco以商品名Watercol™商业出售。这些衍生物保持了IL独特的选择性和色谱性能，并使水可以用作进样溶剂，从而避免了常规色谱柱所需的样品制备程序。这项研究报告并严格讨论了可商购的水相容性IL色谱柱的结果，该色谱柱可通过具有热导率（TCD）和/或火焰电离检测器（FID）的GC直接分析芳香剂和精油领域中的水性样品。结果表明，与水相容的基于IL的固定相可以成功地用于定性和定量分析直接在水性溶剂中稀释的香料和精油。另一方面，研究还表明，当水是样品的主要溶剂时，它们的惰性需要进一步提高，并且（可能）工作温度范围应扩大。