Solid phase microextraction (SPME) is a prevalent extraction technique in which compounds are adsorbed on a polymeric coated fiber, and subsequently desorbed into an instrument for analysis. SPME is classically achieved one of two ways, either sampling above the headspace occurs (headspace SPME) or the fiber is directly submerged into the liquid sample (immersion SPME). For headspace SPME, other techniques have been reported, such as the total vaporization technique (TVT) and high temperature headspace SPME in order to enhance the extraction of non-volatiles or polar analytes for either liquid or solid samples. The combination of derivatization with SPME can often enhance the SPME extraction and the later separation of extracts by gas chromatography (GC) or liquid chromatography (LC). Many derivatization SPME techniques have been reported including, but not limited to, doping fiber and in vial derivatization.  In this work, we combined TVT, high temperature, and in vial derivatization with SPME in one single step. The approach consists of samples being dried in a 20 mL headspace vial, and an insert placed in the same vial with derivatization reagent. Total vaporization of the derivatization reagent then occurs in combination with high temperature headspace SPME. Our approach is easily automated compared to other methods, provides better recovery and GC separation, and also provides the possibility of detecting thermally labile compounds.  This approach has been implemented on the extraction and detection of phytocannabinoids from reference materials, including the thermally labile Δ<sup>9</sup>-tetrahydrocannabinolic acid A (THCA-A).  The optimal amount of derivatization reagent for total vaporization will be discussed in this presentation.<br/>

Total vaporization of derivatization reagent for in situ headspace derivatization solid phase microextraction

253rd National Meeting (2017)

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