Comparison of Solid-Phase Microextraction Using Classical Fibers Versus Mini-Arrows Applying Multiple Headspace Extraction and Various Agitation Techniques

Multiple headspace extraction allowed the comparison of extraction efficiencies for solid-phase microextraction (SPME) using classical fiber-type sorbents versus the relatively novel mini-Arrows. A hydro-alcoholic matrix and two wine aroma compounds (1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) and 2,10,10-trimethyl-6-methylen-1-oxaspiro[4.5]dec-7-ene (vitispirane)) were exemplarily chosen for the evaluation. SPME fiber coating materials were compared with their corresponding SPME mini-Arrow counterparts. With chemically equivalent sorption phases, higher extraction efficiencies were found for the SPME mini-Arrow system due to the larger sorption volume. The comparison of diverse agitation devices revealed a significant influence of the agitation mode on extraction kinetics and extracted analyte amount in non-equilibrium conditions. Furthermore, the evaluation of SPME fibers or SPME mini-Arrow coatings containing a carboxen-type material revealed the importance of an appropriate desorption (injection) temperature. If not chosen carefully, analyte injection may not be complete, possibly resulting in reduced detection limits or generation of carryover problems. Also noteworthy is the construction of the SPME mini-Arrow device as such, as this is more robust compared to the classical SPME fiber, enhancing the lifetime of the extraction device.