A perfumer's work can greatly benefit from investigations of the stabilities and interactions of fragrance materials in consumer products, These investigations (concerning, for example, the shelf life of a cosmetic product or a household product) include isolation of the perfume oil from the finished product. Then individual components of the extracted oil are separated, identified, and finally quantified via high resolution gas chromatography (HRGC) coupled with mass spectrometric detection (MS).
In isolating the fragrance materials, which are usually present only at low levels, the analytical chemist is confronted with a formidable separation challenge, particularly when the sample also contains emulsifiers, surfactants, clarifiers, thickeners, solubilizers, pigments, antioxidant, UV-absorbers, preservatives, solvents, and other materials.
Two of the principal techniques for isolating volatile components like fragrance materials from samples are water or steam hydrodistillation (WSD) and simultaneous hydrodistillation and extraction (SDE). For routine analysis, the most widely used circulatory distillation apparatuses were developed by Sprecher (WSD) and by Likens and Nickerson (SDE). The original apparatus design was modified by several other workers to suit specific requirements. These techniques have many advantages including relative simplicity and ease of operation as well as supposed high efficiency in isolating volatile materials. However, no single method will provide a fragrance profile truly representative of the sample, particularly when the sample contains ingredients of different chemical classes which cover a very wide range of volatilities, solubilities, and polarities. The most appropriate technique will he a compromise based on analytical considerations such as time consumption, accuracy, precision and reproducibility, especially when quantitative work is involved.
