CHAPTER 11: Optical Detection of NPS Internet Products via HPLC-DAD Systems: A Selective Review

For the last few years there has been a sharp increase in the use of novel psychoactive compounds as recreational drugs. They can be ordered via the Internet or in some countries they can be purchased in bricks and mortar shops. Every year, up to 100 new derivatives enter the drug market after slight modification of parent chemical structures. As a consequence, there is a big demand to develop methods for their qualitative and quantitative determination. Especially for the analysis of seized samples, HPLC is a powerful alternative to gas chromatography. Nowadays, HPLC is often coupled to a mass selective detector, but in the case of quantification or purity studies of powder-samples, measurement of UV-absorption is still sufficient as a detection principle, since no problems with too low sample concentration are to be expected. Additionally, many synthetic novel psychoactive compounds contain a stereogenic centre leading to two possible enantiomers. Most probably, the pharmacological potency of the isomers of NPSs (novel psychoactive substances) differ as is the case for many chiral active pharmaceutical ingredients. Therefore, the development of analytical methods for enantioseparation of new psychoactive substances is of great medical and forensic interest. This review deals with the determination of new NPSs internet products by high performance separation techniques, such as HPLC, capillary electrophoresis, capillary electrochromatography and supercritical fluid chromatography with UV detection. Despite the drawbacks of this detection principle compared to mass selective detection, numerous applications are presented for different substance classes.