Abstract
Solid-phase microextraction (SPME) is a well-established sample-preparation technique for environmental studies. The application of SPME has extended from the headspace extraction of volatile compounds to the capture of active components in living organisms via the direct immersion of SPME probes into the tissue (in vivo SPME). The development of biocompatible coatings and the availability of different calibration approaches enable the in vivo sampling of exogenous and endogenous compounds from the living plants and animals without the need for tissue collection. In addition, new geometries such as thin-film coatings, needle-trap devices, recession needles, coated tips, and blades have increased the sensitivity and robustness of in vivo sampling. In this paper, we detail the fundamentals of in vivo SPME, including the various extraction modes, coating geometries, calibration methods, and data analysis methods that are commonly employed. We also discuss recent applications of in vivo SPME in environmental studies and in the analysis of pollutants in plant and animal tissues, as well as in human saliva, breath, and skin analysis. As we show, in vivo SPME has tremendous potential for the targeted and untargeted screening of small molecules in living organisms for environmental monitoring applications.