Direct coupling of Solid Phase Microextraction to Mass Spectrometry: via liquid desorption
The direct coupling of SPME with Mass Spectrometry (MS) analyzers has been investigated for more than 20 years. In fact, different strategies have been developed by several groups worldwide and most have been appropriately reviewed by Fang et al 1 and Deng et al 2 . Given the wide diversity of SPME-MS couplings, it is difficult to categorize them based on one well-defined characteristic. Following a similar approach to the one suggested by Venter et al 3 , one could classify SPME-MS couplings according to the desorption mechanism: solvent 4,5 , thermal 6,7 or laser desorption 8 . Herein, I present a brief summary of the most recent developments on SPME-MS techniques that utilize liquid desorption. Essentially, this field can be divided in three sub-categories: direct-desorption from the extraction substrate 9–11 , desorption into an elution chamber 12 , or desorption into a smaller compartment with efficient ionization (nano-electrospray emitter) 5,13 . As the first category is p