The Analytical Challenge in the Determination of Cathinones, Key-Players in the Worldwide Phenomenon of Novel Psychoactive Substances

Since the turn of the century, the synthesis, availability, and use of new psychoactive substances (NPS) have been increasingly reported worldwide, being considered a complex global phenomenon. As most NPS are not detected in routine drug screening, extra efforts have been made to develop new analytical methods for the detection of these compounds, with several approaches being successfully applied and reported in the literature. The increased traffic of NPS is often related to the limited capacity for detecting and monitoring these compounds, which makes it essential to explore in detail both conventional and more recent approaches to prospect novel sensing strategies and develop in-the-field sensors that are able to detect NPS in a time-efficient manner, within a wide range of concentrations, and in a variety of sample matrices, such as biological samples, wastewater, powders, crystals, and post-mortem specimens. In this context, this review aims to provide an overview of the state of the art in the identification and analytical detection of cathinones, a considerable group within NPS, as well as a critical discussion of the most frequently described sample preparation techniques.