This review addresses the trends in the production of small dimension pre-concentrators for its use in miniaturized total chemical analysis system – µTAS. Pre-concentrators are defined as any device used to enhance the analyte concentration, through its preconcentration and quick release prior to its analysis, in order to guarantee a better detection limit. It is possible to observe that there are few pre-concentrators in the market. Besides showing small dimensions, these devices also present reliability, reproducibility and relatively good cost. The driving forces to these developments were mainly security issues and environmental matters. Practically any chemical analysis might benefit from the manufacturing of miniaturized pre-concentrators. However, some of them would especially benefit. Small amount analyte, generally around ppm or sub-ppm range, and analysis that demand quick response or must occur in situ are the main target to this device development. Therefore, great advance in analyses of medical, biological, environmental and safety areas are expected, besides the development of new materials and theoretical models. Then, new materials, mainly the nanostructured materials, and new models, particularly for adsorption/desorption in miniaturized devices, are to be obtained in the near future and great effort can really be seen. Finally, better detectors aiming better fitting to the device are also in vogue. These detectors can range from small sensors device to complex analytical equipment and most of times miniaturized as well. Not only will the creation of these devices allow cost minimization and quicker analysis time that enables continuous monitoring, but will impact other science and technology areas such as the analytical equipment development. A new approach for preconcentration and/or retention is proposed.
