Development and validation of a quantitative method for the analysis of new psychoactive substances (NPS) in blood

Abstract

The group of drugs of abuse known as new psychoactive substances (NPS) is composed of substances derived from or analogous to classic drugs of abuse, produced to mimic their effects while circumventing law enforcement agencies. NPS represent a major public health problem, with many substances being made available on the illicit market in a short period of time, an increase in the chemical diversity of these compounds, and a lack of knowledge about their acute and chronic toxic effects on humans, leading to hospitalizations and deaths of users following severe intoxications by these agents. The increasing emergence of new compounds and unknown risks of harm to users lead to the challenge of developing new analytical methodologies to detect and identify these substances, and to establish toxic and lethal concentrations. The complex analytical framework of forensic laboratories involves the analysis of many possible toxicants present in extremely varied concentrations in complex biological samples. Instrumental tools must provide flexibility, sensitivity, selectivity, and reliability for detection and determination of multiple targets in these complex matrices where the analyte is usually found in low concentrations. To extract compounds from biological matrices, forensic laboratories generally use conventional sample preparation methods, such as liquid-liquid extraction or solid phase extraction, where there is a high consumption of biological material and organic solvents. Thus, there is interest in the continuous search for new sample preparation techniques that are fast, efficient, automatable and environmentally friendly. Techniques based on microextraction processes are being developed as an alternative to classical methods. These offer major advantages over conventional techniques, such as lower reagent consumption and consequently lower operating costs for the laboratory with the acquisition and disposal of these chemicals; short extraction time; minimum necessary sample volume, important in cases of biological samples with limited availability; and potential automation, which becomes highly relevant in laboratories that need to analyze hundreds of samples per day. The objective of this project is to develop and validate methods for forensic toxicological analysis of NPS in blood. The method for identifying and quantifying NPS will be applied to real biological samples, where the levels found will be correlated with the effects caused by these drugs. Furthermore, the results will be evaluated for the practical applicability of the new techniques in routine forensic toxicology laboratories.