ABSTRACT
Every flavor and aroma analysis problem begins with the same question: How does one select a technique from the myriad well-known isolation methods that will be best suited to the solution of the current problem? The analytical flavor chemist is faced daily with the separation and identification of complex mixtures. These mixtures comprise a wide range of organic chemicals that possess varying polarities and reactivities, usually occur in trace concentrations, and likely are included in other complex organic and inorganic matrices. Fortunately, most aroma chemicals are volatile, and procedures for their isolation from foods and flavors have been established that take advantage of this volatility. Not so advantageous is the length of time usually required to obtain an isolate that is representative of the original aroma or flavor of the sample. The selection of steam distillation, solvent extraction, trapping of the volatiles on adsorbents, or combinations of these methods with other techniques might require several hours before the chemist can begin the chromatographic separation. The simple act of isolation may itself introduce artifacts from impurities in the solvents used, or through decomposition of the matrix or of the flavor chemicals themselves. An ideal approach to flavor isolation and analysis would provide an analytical sample whose composition is identical to the chemical mixture within the matrix, that is free of solvents and other impurities, and that can be completed within a few minutes
with no intermediate processing of the sample. Solid-phase microextraction approaches this ideal.
