The technique is also a preferred technique when sample automation is required and is also a used in screening of samples. It works very well with the less volatiles organics such as PCB's and can be automated. Thermal Desorption is also a very popular technique and is routinely used for the analysis of volatiles in environmental samples as well as food samples. This is important for the analysis of high water content samples such as food products. The Purge and Trap technique is more sensitive by at least a factor of 1000 over headspace techniques.
Typical sensitivity is in the ppb range.
By purging samples at higher temperatures, higher molecular weight compounds can be detected. In addition, very light volatiles and gases will not be trapped on the adsorbent resins and therefore will be missed in the analysis. Volatiles ranging from pentane through the terpenes can readily be analyzed with this technique. Solvent Extraction Solvent extraction has been routinely utilized for the analysis of flavors in foods. However, it has several limitations and disadvantages.