Source identification of amphetamine-like stimulants in Spanish wastewater through enantiomeric profiling

Amphetamine-like substances and synthetic cathinones in Portuguese wastewater influents: Enantiomeric profiling and role of suspended particulate matter

Wastewater based epidemiology (WBE) has been used worldwide to estimate drug consumption routinely. Even though WBE provides valuable data to support legal and health interventions associated to drug use, monitoring studies in Portuguese wastewaters are scarce. Hence, this work aimed to estimate the consumption of some conventional abuse and illicit drugs such as amphetamine (AMP), methamphetamine (MAMP), 3,4-methylenedioxymethamphetamine (MDMA), and the synthetic cathinones buphedrone (BPD), butylone (BTL), 3,4-dimethylmethcathinone (3,4-DMMC) and 3-methylmethcathinone (3-MMC), considering not only the liquid phase, but also the suspended particulate matter (SPM). Moreover, the enantiomeric profiling of the samples was studied, exploring for the first time the possible enantioselective sorption of these drugs onto SPM. For that, 24 h composite raw wastewaters were collected from a conventional wastewater treatment plant (WWTP) in Portugal. After extraction, the liquid phase and SPM extracts were derivatized with an enantiomerically pure reagent and then, analysed using a gas chromatography-mass spectrometry (GC-MS) analytical method. The results showed a low and non-enantioselective adsorption to SPM at environmental relevant levels. Only (S)-AMP was detected in two SPM samples, whereas AMP, MAMP, MDMA, BPD, and 3,4-DMMC were detected in the liquid phase. AMP was the most frequently found drug with an estimated load up to 166.0 mg day-1 1000 people-1 and mostly found with enrichment of (S)-AMP. Nevertheless, (R)-AMP was also determined, which may be related to the consumption of either the illicit racemic AMP or the medicine (R)-deprenyl. The use of MDMA, MAMP and synthetic cathinones (BPD and 3,4-DMMC) was also suggested in Portugal. Nevertheless, the levels and the consumption estimate of the target chemicals were lower than in other European countries or worldwide. These findings provide the first step to the implementation of WBE monitoring campaigns to assess the status of drug consumption in Portuguese communities, contributing to the understanding of drug use patterns and trends worldwide and helping enforce preventive measures.

Simultaneous determination of 28 illegal drugs in sewage by high throughput online SPE-ISTD-UHPLC-MS/MS

This study developed an online solid-phase extraction ultra-high performance liquid chromatography-tandem mass spectrometry (Online-SPE-UHPLC-MS/MS) method for the analysis of 28 illegal drugs in sewage. To achieve this, 28 isotope internal standards (ISTDs) were added to 3 mL sewage samples, the pH was adjusted to 7-8 using hydrochloric acid or 20% ammonia water, followed by centrifugation, filtration, and analysis using UHPLC-MS/MS. The results indicated an excellent linearity of 1-300 ng L-1, and cotinine in the concentration range of 20-6000 ng L-1, linear correlation coefficient R2 > 0.995, with the limit of detection (LOD) of 0.01-6 ng L-1, and a limit of quantification (LOQ) of 0.1-20 ng L-1. The addition of three concentrates of low (2 ng L-1/40 ng L-1), medium (20 ng L-1/400 ng L-1), and high concentration (200 ng L-1/4000 ng L-1) demonstrated the matrix effect of the target compound between ± 22.0%. The extraction recovery was 70.0-119.4%, and a percent accuracy of 75.7-118.1%. Similarly, the intra- and inter-day precisions were 1.8-20.0% and 1.5-18.9%, respectively. The results cemented the sensitivity, accuracy, reliability, strong specificity, and reproducibility, which can be used to screen 28 illegal drugs in sewage for trace analysis.

Tracking methamphetamine and amphetamine consumption patterns in South Korea via enantiomeric analysis of wastewater

Wastewater-based epidemiology (WBE) has emerged as an effective method for monitoring a community's health status and lifestyle. In recent years, enantiomeric profiling has shown promise as a tool for tracing the sources of abused drugs through WBE. This study investigated amphetamine (AMP) and methamphetamine (METH) consumption in South Korea using enantiomeric analysis of untreated wastewater samples collected from 27 wastewater-treatment plants (WWTPs). Both AMP and METH were detected, with the predominant detection of S-(+)-METH indicating widespread illegal use of METH, which is primarily produced by a clandestine synthesis procedure that involves the reduction of ephedrine/pseudoephedrine. Most AMP/METH ratios in the samples were consistent with the expected METH excretion profile, indicating that the presence of AMP was primarily due to METH metabolism. However, R-(-) AMP was detected in 18.5 % and 25.9 % of wastewater samples in winter and spring, respectively, and the high AMP/METH ratio (>0.27) indicated potential AMP abuse. By differentiating between the sources of AMP and METH in wastewater, enantiomeric analysis could help authorities to target and address specific drug-abuse issues affecting the population more effectively.

Wastewater profiling of illicit drugs, an estimation of community consumption: A case study of eThekwini Metropolitan Municipality, South Africa

Estimation of community-wide consumption of illicit drugs through wastewater analysis is a new concept in Africa although widely applied in developed nations as wastewater-based epidemiology (WBE). It is an important tool that can be used in understanding supply and demand patterns of illicit drug use on a local, national, and international scale. Information on illicit drug use is currently limited in Africa, because of a lack of monitoring structures by governments and financial constraints. This study hopes to bridge that gap by contributing to Africa's baseline information on illicit drug use. This study provides the first application of wastewater analysis to quantitatively evaluate daily illicit drug use in the eThekwini Metropolitan Municipality of KwaZulu-Natal Province of South Africa by quantifying the major urinary excreted metabolites, called drug target residues (DTRs), in raw wastewater from four major wastewater treatment plants (WWTPs) sampled for a week. The results showed that cocaine was the dominant illicit drug consumed in the catchment followed by amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine and 3,4-methylenedioxyamphetamine, with a per capita use of 360-3000 mg day-1 1000 inh-1, 47-800 mg day-1 1000 inh-1, 19-120 mg day -1 1000 inh-1, not detected (ND) to 4.9 mg day-1 1000 inh-1, and ND to 410 g day-1 1000 inh-1 respectively. The weekly usage patterns between the four WWTPs differed probably due to the lifestyle of the populace serving the different WWTPs. These results provide useful data on illicit drug use in eThekwini that can be utilised by public health agencies to implement suitable response strategies.

Festivals following the easing of COVID-19 restrictions: Prevalence of new psychoactive substances and illicit drugs

The market for illicit drugs and new psychoactive substances (NPS) has grown significantly and people attending festivals have been identified as being at high risk (high extent and frequency of substance use). Traditional public health surveillance data sources have limitations (high costs, long implementation times, and ethical issues) and wastewater-based epidemiology (WBE) can cost-effectively support surveillance efforts. Influent wastewater samples were analyzed for NPS and illicit drug consumption collected during New Year period (from 29-Dec-2021 to 4-Jan-2022) and a summer Festival (from 29-June-2022 to 12-July-2022) in a large city in Spain. Samples were analyzed for phenethylamines, cathinones, opioids, benzodiazepines, plant-based NPS, dissociatives, and the illicit drugs methamphetamine, MDA, MDMA, ketamine, heroin, cocaine, and pseudoephedrine by liquid chromatography mass spectrometry. High consumption rates of specific NPS and established illicit drugs were identified at the peak of each event. Furthermore, a dynamic change in NPS use (presence and absence of substances) was detected over a period of six months. Eleven NPS, including synthetic cathinones, benzodiazepines, plant-based NPS and dissociatives, and seven illicit drugs were found across both the New Year and summer Festival. Statistically significant differences (p < 0.05) were seen for 3-MMC (New Year vs summer Festival), eutylone (New Year vs summer Festival), cocaine (summer Festival vs normal week and summer Festival vs New Year), MDMA (New Year vs normal week and summer Festival vs normal week), heroin (summer Festival vs New Year) and pseudoephedrine (summer Festival vs New Year). This WBE study assessed the prevalence of NPS and illicit drugs at festivals following the reduction of the COVID-19 pandemic restrictions highlighting the high use of specific substances at the peak of each event. This approach identified in a cost-effective and timely manner without any ethical issues the most used drugs and changes in use patterns and, thus, can complement public health information.

Efficient Validation Strategies in Environmental Analytical Chemistry: A Focus on Organic Micropollutants in Water Samples

This article critically reviews analytical method validation and quality control applied to the environmental chemistry field. The review focuses on the determination of organic micropollutants (OMPs), specifically emerging contaminants and pesticides, in the aquatic environment. The analytical technique considered is (gas and liquid) chromatography coupled to mass spectrometry (MS), including high-resolution MS for wide-scope screening purposes. An analysis of current research practices outlined in the literature has been performed, and key issues and analytical challenges are identified and critically discussed. It is worth emphasizing the lack of specific guidelines applied to environmental analytical chemistry and the minimal regulation of OMPs in waters, which greatly affect method development and performance, requirements for method validation, and the subsequent application to samples. Finally, a proposal is made for method validation and data reporting, which can be understood as starting points for further discussion with specialists in environmental analytical chemistry.

Synthesis of molecularly-imprinted polymers towards a group of amphetamine-type stimulants by reflux precipitation polymerization with a pseudo template

Determination of amphetamine-type drugs (ATSs) in urine and wastewater is a simplified approach for the widespread monitoring of ATSs abuse. To improve the sensitivity of the analytical methods, molecularly imprinted polymers (MIPs) based solid-phase extraction (SPE) pretreatment attracted great attention in this field. Generally, smaller particle sizes and more uniform morphology of the MIPs could provide higher detection sensitivity. Our previous works showed reflux precipitation polymerization (RPP) is a method for synthesizing monodispersed MIPs with small particle size. However, synthesis of uniform spherical MIPs towards a group of targets has never been reported. Therefore, in the present work, MIPs towards a group of ATSs were synthesized via RPP with a pseudo template for the first time. After screening potential pseudo-templates, N-methylphenylethylamine (MPEA) was selected as the optimal pseudo-template. MPEA-MIPs were characterized by scanning electron microscope (SEM), FT-IR spectroscopy and X-ray photoelectron spectroscopy (XPS) spectra. Adsorption isotherms, adsorption kinetics and selectivity were evaluated, and the experimental results indicated that the MPEA-MIPs possessed good selectivity and adsorption property towards ATSs. After optimization of the MIP-SPE procedure, the MIP-SPE cartridges were then coupled with liquid chromatography and tandem mass spectrometry (LC-MS/MS) for determination of ATSs. The evaluation results showed that MIP-SPE-LC-MS/MS displayed good linearity (R² >0.991) in the linear range (1.0-50.0 µg/L for urine and 0.5-50.0 µg/L for wastewater), and low matrix effect (85-112%). The limit of detection (LOD) was 0.05 -0.29 µg/L, and the accuracy (85-115%) and repeatability (RSD ≤ 15%) were satisfactory at low, medium and high concentrations. To the best of our knowledge, this is the first time that dummy MIPs towards a group of ATSs were synthesized by RPP polymerization, which showed great potential for the detection of ATSs in urine and wastewater.

Refining the estimation of amphetamine consumption by wastewater-based epidemiology

Consumption of amphetamine and methamphetamine, two common illicit drugs, has been monitored by wastewater-based epidemiology (WBE) in many countries over the past decade. There is potential for the estimated amount of amphetamine used to be skewed at locations where methamphetamine is also consumed, because amphetamine is also excreted to wastewater following methamphetamine consumption. The present study aims to review the available data in the literature to identify an average ratio of amphetamine/methamphetamine (AMP/METH) that is excreted to wastewater after methamphetamine consumption. This ratio could then be used to refine the estimation of amphetamine consumption in catchments where there is both amphetamine and methamphetamine use. Using data from more than 6000 wastewater samples from Australia where methamphetamine is the dominant illicit amphetamine-type substance on the market, we were able to subtract the contribution of legal sources of amphetamine contribution and obtain the median AMP/METH ratio in wastewater of 0.09. Using this value, the amphetamine derived from methamphetamine consumption can be calculated and subtracted from the total amphetamine mass loads in wastewater samples. Without considering the contribution of amphetamine from methamphetamine use, selected European catchments with comparable consumption of amphetamine and methamphetamine showed up to 83% overestimation of amphetamine use. For catchments with AMP/METH ratio greater than 1.00, the impact of amphetamine from methamphetamine would be negligible; for catchments with AMP/METH ratio in the range of 0.04-0.19, it will be difficult to accurately estimate amphetamine consumption.

Use of illicit drugs, alcohol and tobacco in Spain and Portugal during the COVID-19 crisis in 2020 as measured by wastewater-based epidemiology

The COVID-19 pandemic spread rapidly worldwide in the year 2020, which was initially restrained by drastic mobility restrictions. In this work, we investigated the use of illicit drugs (amphetamine, methamphetamine, ecstasy, cocaine and cannabis), and licit substances of abuse (alcohol and tobacco) during the earlier months (March-July 2020) of the pandemic restrictions in four Spanish (Bilbao and its metropolitan area, Vitoria-Gasteiz, Castellón and Santiago de Compostela) and two Portuguese (Porto and Vila do Conde) locations by wastewater-based epidemiology (WBE). The results show that no methamphetamine was detected in any of the locations monitored, while amphetamine use was only detectable in the two locations from the Basque Country (Bilbao and its metropolitan area and Vitoria-Gasteiz), with high estimated average usage rates (700-930 mg day-1 1000 inhabitant-1). The remaining substances were detected in all the investigated catchment areas. In general, no remarkable changes were found in population normalized loads compared to former years, except for cocaine (i.e. its main metabolite, benzoylecgonine). For this drug, a notable decrease in use was discernible in Castellón, while its usage in Porto and Santiago de Compostela seemed to continue in a rising trend, already initiated in former years. Furthermore, two events of ecstasy (3,4-methylenedioxymethamphetamine, MDMA) dumping in the sewage network were confirmed by enantiomeric analysis, one in Santiago de Compostela just prior the lockdown and the second one in the Bilbao and its metropolitan area in July after relieving the more stringent measures. The latter could also be associated with a police intervention. The comparison of WBE with (web) survey data, which do not provide information at a local level, points towards contradictory conclusions for some of the substances, thereby highlighting the need for stable WBE networks capable of near real-time monitoring drug use.

Enantiomeric profiling of amphetamines in wastewater using chiral derivatisation with gas chromatographic-tandem mass spectrometric detection

Enantiomeric profiling can supplement wastewater-based epidemiology (WBE) by providing additional information on drug origin (licit or illicit), improving consumption estimates, i.e., differentiating between disposal and consumption, and offering an insight into the potency of drugs available on the illicit drug market. We report on the enantiomeric profiling of amphetamines in wastewater using R(-)-α-methoxy-α-(trifluoromethyl) phenylacetyl chloride (R-MTPCl), a chiral derivatising agent and GC-MS/MS. The method performed well when evaluated against the SANTE/12682/2019 guidelines in terms of recovery (81-99%), accuracy (99-111%), repeatability (1-8%RSD) and linearity (LOQ-1000 ng/mL). The LOD and LOQ were 120 ng/L and 400 ng/L, respectively. The method was applied to samples of raw wastewater from two Slovene municipalities with unusual levels of amphetamines: Ljubljana (LJ1) and Velenje (VE1). LJ1 had an anomalously high mass load of MDMA (3,4-methylenedioxymethamphetamine) identified during SCORE 2020, and VE1 is a representative sample of the consistently high mass load of amphetamine. A second Ljubljana sample (LJ2) was chosen as a representative sample. The presence of racemic MDMA (EF = 0.511) in LJ1 indicated the disposal of the unused drug into the sewer, while the enrichment of R-MDMA (EF = 0.666) in the combined extract sample from Ljubljana (LJ2) indicated consumption. In the case of Velenje and Ljubljana, it is impossible to distinguish between the direct disposal and consumption of amphetamine and methamphetamine. Also, since amphetamine/methamphetamine-based prescription medications are unavailable in Slovenia, racemic amphetamine in VE1 (EF = 0.514) and LJ2 (EF = 0.459) indicate racemic and the more potent S-amphetamine are sold on the illicit drug market. Only S-methamphetamine was detected in wastewater (LJ2: EF = 0), indicating the presence of only the more potent S-methamphetamine on the illicit drug market. Overall, enantiomeric profiling provided useful information on amphetamine residues. In addition, chiral derivatisation can be a cost-effective alternative to using chiral chromatographic columns for the enantiomeric profiling of amphetamines in wastewater.