General Methods of Sample Preparation for Infrared Hyphenated Techniques
In applications, such as perfumery, the construction of complicated molecular mixtures is the purposeful objective. Because of the difficulty and importance of the task, multiple analytical techniques are combined to form what are often called hyphenated techniques. This chapter provides an overview of techniques of molecular mixture analysis which involve Fourier-Transform-Infrared (FT-IR) as the spectrometric detector. It discusses sample preparation for gas chromatography/Fourier-Transform-Infrared in detail, since the latter is the most developed and practiced of the techniques which combine chromatography and FT-IR. The major factor in satisfactory sample preparation for thermogravimetric/FT-IR is control of particle size. Solvent extraction, in addition to and in combination with distillation, has probably been the most used technique of the classical laboratory synthetic procedures adapted to the service of gas chromatography sample preparation. Supercritical fluid extraction may replace older methods of sample preparation, both at the analytical and synthetic scale of operation.