Nondestructive Sampling of Living Systems Using in Vivo Solid-Phase Microextraction

Solid-phase microextraction (SPME) approaches have been widely used for invasive and noninvasive studies as a simple, miniaturized, fast, and environmentally friendly sampling and sample preparation technique. SPME is a solvent-free sample preparation technique and combines sampling, analyte isolation, and enrichment into one step. In vivo analysis is a special application area where SPME is gaining ground because of its unique format and convenient device design. SPME can be performed using three basic extraction modes, direct extraction, headspace extraction, and membrane-protected extraction. SPME eliminates or minimizes the use of organic solvents, integrates sampling and sample preparation, and therefore substantially reduces the total time and cost of analysis. To understand the kinetics of SPME process, Prandtl boundary layer model can be used for simplification of corresponding equations. The performance of SPME is critically dependent on the properties of the extraction phase, which determine the selectivity and the reliability of the method.