Qualitative fingerprinting of psychoactive pharmaceuticals, illicit drugs, and related human metabolites in wastewater: A year-long study from Riga, Latvia

Trends and challenges in analytical chemistry for multi-analysis of illicit drugs employing wastewater-based epidemiology

“…The sampling methodology directly affects the representativeness of the samples [ 30 ], so for this reason, 24-h composite sampling of wastewater using active sampling with autosamplers has been the predominant approach [ 1 – 3 , 5 – 7 , 11 , 12 , 31 , 32 ]. Given that autosamplers are sophisticated equipment, other sampling strategies have also been used, such as short sampling times [ 17 ] and grab sampling [ 20 , 33 , 34 ].…”

“…Wastewater samples are chemically complex mixtures with analytes present at very low concentrations (on the order of nanograms per liter), so the analysis requires the application of effective sample preparation methods to remove interferents and preconcentrate the target analytes, in order to provide greater sensitivity in the analytical determination of IDBs [ 29 , 47 ]. SPE is the predominant sample preparation technique used in WBE research [ 5 , 48 ]. Most studies have employed offline SPE [ 1 , 6 , 9 , 11 , 21 , 23 , 24 , 37 ], where sample preparation and chromatographic analysis are performed separately [ 26 ].…”

“…The selection of an appropriate sorbent for SPE is crucial, since it must ensure effective extraction and recovery of the analytes, without any significant losses [ 1 ]. The type of sorbent employed must consider the properties and the chemical structures of the target IBDs [ 5 ]. Reversed-phase sorbents with hydrophilic and lipophilic properties, such as Oasis HLB and Strata-X (Phenomenex, CA, USA), have been extensively used in the multi-analysis of molecules in a wide polarity range, providing good recovery percentages in the extraction of IDBs [ 9 , 11 , 12 , 31 , 37 , 41 ].…”

“…According to the 2022 World Drug Report, 284 million people worldwide, aged from 15 to 64 years, used a drug in 2020, representing a 26% increase over 2010 data [ 4 ]. Drug consumption leads to environmental and health concerns, because wastewater treatment plants (WWTPs) are not designed to completely remove these compounds, which are considered emerging contaminants [ 5 – 8 ].…”

“…The application of WBE for drug detection allows the estimation of short- and long-term consumption levels, with the advantages of being a faster, direct (almost real-time), noninvasive, accurate, and less laborious tool, compared to the use of population surveys [ 1 , 3 , 8 , 11 ]. It is possible to investigate temporal trends of drug use by the community [ 3 , 16 ] and in educational institutions [ 17 ], the use of new psychoactive substances (NPS) [ 18 , 19 ], the influence of weekends and national holidays [ 20 ], festive events [ 6 , 20 ], seasons [ 1 , 9 ], and music events [ 12 , 21 ], and the impact of social isolation measures imposed due to crises such as the COVID-19 pandemic [ 5 , 10 , 22 – 25 ].…”