Many interactions in natural systems are governed by odors. In our studies of semiochemical-based plant, insect, and microorganism communications we have routinely utilized dynamic collections on adsorption polymers (i.e., Super Q) followed by solvent extraction, or static collection on solid phase microextraction fibers (SPME). However, we have had a continual need for new or improved methods to collect and identify semiochemicals that, in addition to having high sensitivity, are simple and reliable. Ideally, these methods should be solvent free, allowing for shorter sampling times and free of solvent peaks that might exclude detection of potentially important highly volatile compounds. A crucial step toward these goals was the development of a simple thermal desorption system as an alternative to Super Q collection, and more recently, the addition of a new needle trap technique that combines dynamic sampling with the ease of a SPME-like injection technique. Although these solventless techniques all are powerful, it is not always clear under what situation which method would be preferred over another, and in what way their inherent strengths and weaknesses might affect the analysis results. Discussed will be a comparison of Tenax/thermal desorption, SPME, and needle trap collections where all techniques were used to collect a volatile blend of known composition and concentration. We investigated the quantitative and qualitative effect of factors like equilibrium and sampling time as well as how the results were affected by factors such as sorbent capacity and sampling breakthrough. Furthermore, we explored how the results might also be affected by the desorption technique including the use of pulse desorption and/or cold trap focusing. The presented results will be used as a guide for technique selection for our group, as well as our chemical ecology colleagues.<br/>

Solventless sampling and GC/MS analyses: A comparative study of three volatile collection techniques

256th National Meeting (2018)

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