New challenges in (bio)analytical sample treatment procedures for clinical applications

The primary cause of poor and ambiguous results obtained from bioanalytical process is the sample pre-treatment, especially in clinical analysis, e.g., because it involves dealing with complex sample matrices, such as whole blood, urine, saliva, serum and plasma. So, the aim of this review is to focus the attention on classical and new techniques of pre-treatment for biological samples used in the bioanalytical process. We discussed the methods generally used for these types of complex samples. Undoubtedly, it is a daunting task to deal with biological samples because the analyst may encounter substantial loss of the analytes of interest, or the overall analysis may be too much time consuming. Nowa-days, we are inclined to use green solvents for the environment, but without sacrificing the analytical performance and selectivity. All the characteristics mentioned above should be added to the difficulty of withdrawal of samples like blood, because it can be an invasive practice. For these reasons, now we can also find in the literature, the use of saliva as an alternative biological sample and new techniques that don’t require substantial sample pre-treatment such as fabric phase sorptive extraction (FPSE). The text has been divided into two distinct parts: in the first one, we described clinical applications under different subsections such as anticancer drugs, antibiotics, vitamins, antivirals, non-steroidal an-ti-inflammatory drugs, statin, imidazoles and triazoles. The second part is dedicated to sample preparation techniques for diagnostic purposes and is divided into different sam-ple preparation techniques: solid phase microextraction (SPME), Microextraction by packed sorbent (MEPS), Dispersive liquid–liquid microextraction (DDLME), and Fabric Phase Sorptive Extraction (FPSE).