Recent trends in sampling and sorbent-based sample preparation procedures for bioanalytical applications

In the last century, in the analytical field, the interest of researchers in the preliminary phases of the analysis has grown more and more, giving space to important innovations in the field of sample preparation, but above all leading to a renewed interest in this field. It is known that these phases are the most critical of the entire analytical process not only in terms of time, but also in terms of final measurement error. In this perspective, in recent years a growing interest of the Scientific Community and important efforts have been directed towards not only the development of innovative techniques that allow a reduction in sample manipulation while maintaining high analytical performance, but at the same time also towards a reduction in the environmental impact that such procedures can have. In this direction, there is also the possibility of intervening to reduce the quantity of sample processed and, consequently, obtain a reduction in the volumes of solvents and non-green reagents. The main objective of this review is to provide an overview of the literature focused on the most modern sorbent-based sampling and sample preparation techniques that are applied (or have been recently developed) in the three main "sections" of instrumental analysis (sensor-based analysis, electrochemical analysis and chromatography-based analysis). In particular, the Authors wanted to outline the main advantages and disadvantages of the different procedures and above all evaluate how the different methods are applied in the field of biological matrix analysis (biological fluids, tissues, etc.). A final paragraph also considers an evaluation and estimate (using the most recent tools) for the environmental impact assessment and how they can be applied in this field (AGREE, AGREEprep, and MoGAPI). Through these applications it is also evaluated how continuous improvement is possible by checking the "critical" points and remedying/optimizing the procedures in this sense. The present review finally concludes with a section on future perspectives in which the Authors (based on their vast experience in their respective fields of application) have tried to hypothesize a possible future and a possible way to be considered to ensure that this part of the analytical process can further progress and support the new challenges that daily arise in the field of bioanalytical applications.