Simultaneous distillation/adsorption technique

Solid-phase microextraction is an adsorption/desorption technique used to analyze the volatile and non-volatile compounds in both liquid and gaseous samples used as an alternative to the headspace, purge-and-trap, solid-phase extraction, or simultaneous distillation/extraction techniques. Analytes are thermally desorbed and directly introduced into any gas chromatograph or GC/mass spectrometry (MS) system. When coupled to HPLC with the proper interface, the analytes are washed out of the fiber by the mobile phase. 

The search of adequate extraction techniques allowing the identification and quantification of wine volatile compounds has attracted the attention of many scientists. This has resulted in the availability of a wide range of analytical tools for the extraction of these compounds from wine. These methodologies are mainly based on the solubility of the compounds in organic solvents (liquid-liquid extraction LLE, simultaneous distillation liquid extraction SDE), on their volatility (static and dynamic headspace techniques), or based on their sorptive/adsorptive capacity on polymeric phases (solid phase extraction SPE, solid phase microextraction SPME, stir bar sorptive extraction SBSE). In addition, volatile compounds can be extracted by methods based on combinations of some of these properties (headspace solid phase microextraction HS-SPME, solid phase dynamic extraction SPDE). 

Three commonly used extraction techniques for the analysis of aroma are simultaneous distillation/extraction (SDE), dynamic headspace adsorption on Tenax TA (Buchem N.V., Apeldoorn, The Netherlands), and solid-phase microextraction (SPME) [1,2]. All of these techniques have positive aspects and drawbacks, and these are described. In SDE the sample is boiled for 1 to 2 hr and so precooking may not be necessary, although the meat is usually minced to maximize surface area for the extraction process. The other techniques can be used to examine either a chopped or a whole piece of cooked meat. 

Simultaneous distillation/extraction, headspace adsorption on Tenax TA, and SPME have all been widely described. The discussion here is confined to the merits and drawbacks of these techniques. 

The SDK procedure was performed using a micro-version of a Likens-Nickerson apparatus [33] in the configuration for heavier-than-water solvents. The aroma components were extracted by steam distillation and the aqueous distillate was simultaneously extracted with dichloromethane. The organic extracts were analyzed by GC-FID and GC-MS. The DHS technique was carried out with adsorption on Tenax traps and thermal desorption with ctyofocusing of the volatile substances into the GC capillary column. 

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