Enantiomeric profiling of chiral pharmacologically active compounds (PACs) in the environment has hardly been investigated. This manuscript describes, for the first time, a multi-residue enantioselective method for the analysis of human and veterinary chiral PACs and their main metabolites from different therapeutic groups in complex environmental samples such as wastewater and river water. Several analytes targeted in this paper have not been analysed in the environment at enantiomeric level before. These are aminorex, carboxyibuprofen, carprofen, cephalexin, 3-N-dechloroethylifosfamide, 10,11-dihydro-10-hydroxycarbamazepine, dihydroketoprofen, fenoprofen, fexofenadine, flurbiprofen, 2-hydroxyibuprofen, ifosfamide, indoprofen, mandelic acid, 2-phenylpropionic acid, praziquantel and tetramisole. The method is based on chiral liquid chromatography utilising a chiral α1-acid glycoprotein column and tandem mass spectrometry detection. Excellent chromatographic separation of enantiomers (Rs≥1.0) was achieved for chloramphenicol, fexofenadine, ifosfamide, naproxen, tetramisole, ibuprofen and their metabolites: aminorex and dihydroketoprofen (three of four enantiomers), and partial separation (Rs = 0.7–1.0) was achieved for ketoprofen, praziquantel and the following metabolites: 3-N-dechloroethylifosfamide and 10,11-dihydro-10-hydroxycarbamazepine. The overall performance of the method was satisfactory for most of the compounds targeted. Method detection limits were at low nanogram per litre for surface water and effluent wastewater. Method intra-day precision was on average under 20 % and sample pre-concentration using solid phase extraction yielded recoveries >70 % for most of the analytes. This novel, selective and sensitive method has been applied for the quantification of chiral PACs in surface water and effluent wastewater providing excellent enantioresolution of multicomponent mixtures in complex environmental samples. It will help with better understanding of the role of individual enantiomers in the environment and will enable more accurate environmental risk assessment.

•Critical review of literature regarding chiral analysis of drugs in environmental matrices.•Summary of research carried out in this area, including methods and results.•Sampling highlighted as an under investigated area.•Chiral LC noted as a bottle neck in the advancement of the field.•Environmental results linked with eco-toxicological data.The aim of this paper is to introduce the subject of chirality within pharmaceuticals and its implications in environmental contamination. The paper describes contemporary techniques and stationary phases in the analysis of chiral pharmaceuticals and illicit drugs, the main focus being on liquid chromatography coupled with mass spectrometry. A critical review of the methods employed including sample collection, preparation and analysis is undertaken. Special attention is paid to the possible analytical pitfalls of chromatographic separations at enantiomeric level, which could potentially lead to erroneous measurements of enantiomers. Several applications of chiral analysis and results gained in the field are also discussed. Among them are: (i) study of fate and effects of chiral pharmaceuticals in the environment and during wastewater treatment, (ii) estimation of community-wide drugs use via newly emerging field of sewage epidemiology and (iii) usage of chiral drugs as chemical markers of water contamination with sewage. The paper also aims to identify gaps within current knowledge.

This paper describes the development and application of a multi-residue chiral liquid chromatography coupled with tandem mass spectrometry method for simultaneous enantiomeric profiling of 18 chiral pharmaceuticals and their active metabolites (belonging to several therapeutic classes including analgesics, psychiatric drugs, antibiotics, cardiovascular drugs and β-agonists) in surface water and wastewater. To the authors’ knowledge, this is the first time an enantiomeric method including such a high number of pharmaceuticals and their metabolites has been reported. Some of the pharmaceuticals have never been studied before in environmental matrices. Among them are timolol, betaxolol, carazolol and clenbuterol. A monitoring programme of the Guadalquivir River basin (South Spain), including 24 sampling sites and five wastewater treatment plants along the basin, revealed that enantiomeric composition of studied pharmaceuticals is dependent on compound and sampling site. Several compounds such as ibuprofen, atenolol, sotalol and metoprolol were frequently found as racemic mixtures. On the other hand, fluoxetine, propranolol and albuterol were found to be enriched with one enantiomer. Such an outcome might be of significant environmental relevance as two enantiomers of the same chiral compound might reveal different ecotoxicity. For example, propranolol was enriched with S(−)-enantiomer, which is known to be more toxic to Pimephales promelas than R(+)-propranolol. Fluoxetine was found to be enriched with S(+)-enantiomer, which is more toxic to P. promelas than R(−)-fluoxetine.

The aim of this paper is to discuss the enantiomer-specific fate of chiral drugs during wastewater treatment and in receiving waters. Several chiral drugs were studied: amphetamine-like drugs of abuse (amphetamine, methamphetamine, MDMA, MDA), ephedrines (ephedrine and pseudoephedrine), antidepressant venlafaxine, and beta-blocker atenolol. A monitoring program was undertaken in 7 WWTPs (utilizing mainly activated sludge and trickling filters technologies) and at 6 sampling points in receiving waters over the period of 9 months. The results revealed the enantiomer-specific fate of all studied drugs during both wastewater treatment and in the aqueous environment. The extent of stereoselectivity depended on several parameters including: type of chiral drug (high stereoselectivity was recorded for atenolol and MDMA), treatment technology used (activated sludge showed higher stereoselectivity than trickling filters), and season (higher stereoselectivity was observed in the aqueous environment over the spring/summer time).

This paper presents and compares for the first time two chiral LC–QTOF-MS methodologies (utilising CBH and Chirobiotic V columns with cellobiohydrolase and vancomycin as chiral selectors) for the quantification of amphetamine, methamphetamine, MDA (methylenedioxyamphetamine), MDMA (methylenedioxymethamphetamine), propranolol, atenolol, metoprolol, fluoxetine and venlafaxine in river water and sewage effluent. The lowest MDLs (0.3–5.0 ng L−1 and 1.3–15.1 ng L−1 for river water and sewage effluent respectively) were observed using the chiral column Chirobiotic V. This is with the exception of methamphetamine and MDMA which had lower MDLs using the CBH column. However, the CBH column resulted in better resolution of enantiomers (Rs = 2.5 for amphetamine compared with Rs = 1.2 with Chirobiotic V). Method recovery rates were typically >80% for both methodologies. Pharmaceuticals and illicit drugs detected and quantified in environmental samples were successfully identified using MS/MS confirmation. In sewage effluent, the total beta-blocker concentrations of propranolol, atenolol and metoprolol were on average 77.0, 1091.0 and 3.6 ng L−1 thus having EFs (Enantiomeric Fractions) of 0.43, 0.55 and 0.54 respectively. In river water, total propranolol and atenolol was quantified on average at <10.0 ng L−1. Differences in EF between sewage and river water matrices were evident: venlafaxine was observed with respective EF of 0.43 ± 0.02 and 0.58 ± 0.02.Highlights► Here two chiral LC–QTOF-MS methods are detailed for the analysis of pharmaceuticals and illicit drugs. ► Methods are suitable for resolving and quantifying chiral compounds in river and wastewater. ► Chiral compounds quantified in environment samples were confirmed using MS/MS confirmation. ► Differences in EF between compounds in sewage and river water were evident.

A new-multi residue method was developed for the environmental monitoring of 65 stimulants, opiod and morphine derivatives, benzodiazepines, antidepressants, dissociative anaesthetics, drug precursors, human urine indicators and their metabolites in wastewater and surface water. The proposed analytical methodology offers rapid analysis for a large number of compounds, with low limits of quantification and utilises only one solid-phase extraction–ultra performance liquid chromatography–positive electrospray ionisation tandem mass spectrometry (SPE–LC–MS/MS) method, thus overcoming the drawbacks of previously published procedures. The method employed solid phase extraction with the usage of Oasis MCX sorbent and subsequent ultra performance liquid chromatography–positive electrospray ionisation tandem mass spectrometry. The usage of a 1.7 μm particle size column (1 mm × 150 mm) resulted in very low flow rates (0.04 mL min−1), and as a consequence gave good sensitivity, low mobile phase consumption and short retention times for all compounds (from 2.9 to 23.1 min). High SPE recoveries (>60%) were obtained for the majority of compounds. The mean correlation coefficients of the calibration curves were typically higher than 0.997 and showed good linearity in the range 0–1000 μg L−1. The method limits of detection ranged from 0.1 ng L−1 for compounds including cocaine, benzoylecgonine, norbenzoylecgonine and 2-oxo-3-hydroxy-LSD to 100 ng L−1 for caffeine. Method quantification limits ranged from 0.5 to 154.2 ng L−1. Intra- and inter-day repeatabilities were on average less than 10%. The method accuracy range was within −33.1 to 30.1%. The new multi-residue method was used to analyse drugs of abuse in wastewater and river water in the UK environment. Of the targeted 65 compounds, 46 analytes were detected at levels above the method quantification limit (MQL) in wastewater treatment plant (WWTP) influent, 43 in WWTP effluent and 36 compounds in river water.

Presented is the first comprehensive study of drugs of abuse on suspended particulate matter (SPM) in wastewater. Analysis of SPM is crucial to prevent the under-reporting of the levels of analyte that may be present in wastewater. Analytical methods to date analyse the aqueous part of wastewater samples only, removing SPM through the use of filtration or centrifugation. The development of an analytical method to determine 60 compounds on SPM using a combination of pressurised liquid extraction, solid phase extraction and liquid chromatography coupled with tandem mass spectrometry (PLE-SPE-LC–MS/MS) is reported. The range of compounds monitored included stimulants, opioid and morphine derivatives, benzodiazepines, antidepressants, dissociative anaesthetics, drug precursors, and their metabolites. The method was successfully validated (parameters studied: linearity and range, recovery, accuracy, reproducibility, repeatability, matrix effects, and limits of detection and quantification). The developed methodology was applied to SPM samples collected at three wastewater treatment plants in the UK. The average proportion of analyte on SPM as opposed to in the aqueous phase was <5% for several compounds including cocaine, benzoylecgonine, MDMA, and ketamine; whereas the proportion was >10% with regard to methadone, EDDP, EMDP, BZP, fentanyl, nortramadol, norpropoxyphene, sildenafil and all antidepressants (dosulepin, amitriptyline, nortriptyline, fluoxetine and norfluoxetine). Consequently, the lack of SPM analysis in wastewater sampling protocol could lead to the under-reporting of the measured concentration of some compounds.Highlights► First multi-residue PLE-SPE-LC–MS/MS method to analyse drugs of abuse in suspended particulate matter (SPM) in wastewater. ► 60 drugs of abuse and associated metabolites were monitored. ► Method validation: MQLs: 0.06–20 ng g−1; precision: <20%; accuracy: ±18%; PLE recovery: ≥56%. ► The average proportion of several antidepressants on SPM was >40%. ► Lack of SPM analysis could lead to under-reporting of concentrations of certain drugs in wastewater.

The main aim of this manuscript is to provide a comprehensive and critical verification of methodology commonly used for sample collection, storage and preparation in studies concerning the analysis of pharmaceuticals and illicit drugs in aqueous environmental samples with the usage of SPE-LC/MS techniques. This manuscript reports the results of investigations into several sample preparation parameters that to the authors’ knowledge have not been reported or have received very little attention. This includes: (i) effect of evaporation temperature and (ii) solvent with regards to solid phase extraction (SPE) extracts; (iii) effect of silanising glassware; (iv) recovery of analytes during vacuum filtration through glass fibre filters and (v) pre LC–MS filter membranes. All of these parameters are vital to develop efficient and reliable extraction techniques; an essential factor given that target drug residues are often present in the aqueous environment at ng L−1 levels. Presented is also the first comprehensive review of the stability of illicit drugs and pharmaceuticals in wastewater. Among the parameters studied are: time of storage, temperature and pH. Over 60 analytes were targeted including stimulants, opioid and morphine derivatives, benzodiazepines, antidepressants, dissociative anaesthetics, drug precursors, human urine indicators and their metabolites. The lack of stability of analytes in raw wastewater was found to be significant for many compounds. For instance, 34% of compounds studied reported a stability change >15% after only 12 h in raw wastewater stored at 2 °C; a very important finding given that wastewater is typically collected with the use of 24 h composite samplers. The stability of these compounds is also critical given the recent development of so-called ‘sewage forensics’ or ‘sewage epidemiology’ in which concentrations of target drug residues in wastewater are used to back-calculate drug consumption. Without an understanding of stability, under (or over) reporting of consumption estimations may take place.Highlights► Critical assessment of sample collection, storage and preparation for >60 drugs of abuse. ► First comprehensive stability study of drugs of abuse in wastewater. ► 24 h composite samplers are unsuitable with regards to some compounds due to poor stability. ► Silanisation of vials during the evaporation of SPE extracts is critical in achieving high SPE recoveries. ► There is a need for more rigorous reporting of method validation data.

Pharmacologically active compounds including both legally used pharmaceuticals and illicit drugs are potent environmental contaminants. Extensive research has been undertaken over the recent years to understand their environmental fate and toxicity. The one very important phenomenon that has been overlooked by environmental researchers studying the fate of pharmacologically active compounds in the environment is their chirality. Chiral drugs can exist in the form of enantiomers, which have similar physicochemical properties but differ in their biological properties such as distribution, metabolism and excretion, as these processes (due to stereospecific interactions of enantiomers with biological systems) usually favour one enantiomer over the other. Additionally, due to different pharmacological activity, enantiomers of chiral drugs can differ in toxicity. Furthermore, degradation of chiral drugs during wastewater treatment and in the environment can be stereoselective and can lead to chiral products of varied toxicity. The distribution of different enantiomers of the same chiral drug in the aquatic environment and biota can also be stereoselective. Biological processes can lead to stereoselective enrichment or depletion of the enantiomeric composition of chiral drugs. As a result the very same drug might reveal different activity and toxicity and this will depend on its origin and exposure to several factors governing its fate in the environment. In this critical review a discussion of the importance of chirality of pharmacologically active compounds in the environmental context is undertaken and suggestions for directions in further research are made. Several groups of chiral drugs of major environmental relevance are discussed and their pharmacological action and disposition in the body is also outlined as it is a key factor in developing a full understanding of their environmental occurrence, fate and toxicity. This review will be of interest to environmental scientists, especially those interested in issues associated with environmental contamination with pharmacologically active compounds and chiral pollutants. As the review will outline current state of knowledge on chiral drugs, it will be of value to anyone interested in the phenomenon of chirality, chiral drugs, their stereoselective disposition in the body and environmental fate (212 references).

•Wastewater biomarkers provide information on lifestyle habits, health and wellbeing.•Specific criteria should be followed to select a suitable biomarker.•Report of the current knowledge of the most relevant biomarkers used so far•Proposal of potential wastewater biomarkers for future applications•Review of pharmacokinetic data and stability in urine and wastewater for each biomarkerThe information obtained from the chemical analysis of specific human excretion products (biomarkers) in urban wastewater can be used to estimate the exposure or consumption of the population under investigation to a defined substance. A proper biomarker can provide relevant information about lifestyle habits, health and wellbeing, but its selection is not an easy task as it should fulfil several specific requirements in order to be successfully employed. This paper aims to summarize the current knowledge related to the most relevant biomarkers used so far. In addition, some potential wastewater biomarkers that could be used for future applications were evaluated. For this purpose, representative chemical classes have been chosen and grouped in four main categories: (i) those that provide estimates of lifestyle factors and substance use, (ii) those used to estimate the exposure to toxicants present in the environment and food, (iii) those that have the potential to provide information about public health and illness and (iv) those used to estimate the population size. To facilitate the evaluation of the eligibility of a compound as a biomarker, information, when available, on stability in urine and wastewater and pharmacokinetic data (i.e. metabolism and urinary excretion profile) has been reviewed. Finally, several needs and recommendations for future research are proposed.

•First method developed for micropollutants in Phragmites australis.•Multi-residue determination of 81 micropollutants.•Method quantitation limits were <5 ng g−1 dry weight.•17 micropollutants (including metabolites) found up to 200 ng g−1.In constructed wetlands micropollutants can be removed from water by phytoremediation. However, micropollutant uptake and metabolism by plants here is poorly understood due to the lack of good analytical approaches. Reported herein is the first methodology developed and validated for the multi-residue determination of 81 micropollutants (pharmaceuticals, personal care products and illicit drugs) in the emergent macrophyte Phragmites australis. The method involved extraction by microwave accelerated extraction (MAE), clean-up using off-line solid phase extraction and analysis by ultra-high-performance liquid chromatography tandem mass spectrometry. Development of the MAE method found the influence of studied variables on micropollutant recovery to be: extraction temperature > sample mass > solvent composition. Validation of the developed extraction protocol revealed method recoveries were in the range 80–120% for the majority of micropollutants. Method quantitation limits (MQLs) were generally <5 ng g−1 dry weight demonstrating the sensitivity of the methodology. Application of the method to P. australis from a constructed wetland used to treat trickling filter effluent found 17 micropollutants above their MQL, up to concentrations of 200 ng g−1. Other than uptake, the presence of several metabolites (carbamazepine 10,11 epoxide, desvenlafaxine, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine, N-desmethyltramadol and norketamine) indicated metabolism within the plant may also occur. This new analytical methodology will enable a process mass balance of the constructed wetland to be attained for the first time, and thus help understand the role of phytoremediation in micropollutant removal by such systems.Figure optionsDownload full-size imageDownload high-quality image (210 K)Download as PowerPoint slide

This manuscript reports, for the first time, a monitoring study analysing wastewater and associated suspended particulate matter (SPM) to determine the concentration of drugs of abuse and metabolites in wastewater influent. The monitoring of SPM is crucial for target analytes because, depending on their physico-chemical properties, they may partition to particulates; thus, analysis of wastewater only will result in under-reporting of the concentration of target analytes in the sample. A daily one week monitoring study was carried out at a WWTP serving one of the largest cities in the Czech Republic; representing the first comprehensive application of the sewage epidemiology approach in the Czech Republic. In total, 60 analytes were targeted in the monitoring programme including stimulants, opioid and morphine derivatives, benzodiazepines, antidepressants, dissociative anaesthetics, drug precursors and their metabolites. Analysis of SPM determined that significant proportions of some compounds were present on the solids. For example, 21.0–49.8% of the total concentration of EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine) in the sample was determined on SPM and 11.2–19.6% of methadone. The highest proportion on SPM was determined for fluoxetine in the range 68.1–79.6%, norfluoxetine 46.6–61.9% and amitriptyline 21.8–51.2%. In contrast, some compounds presented very little partitioning to SPM. Less than 5% was determined partitioned to SPM over the week period for analytes including cocaine, benzoylecgonine, cocaethylene, amphetamine, methamphetamine, MDMA (3,4-methylenedioxymethamphetamine), codeine, dihydrocodeine, tramadol, nortramadol, oxazepam and ephedrine. Determined concentrations in wastewater influent were subsequently utilised in the sewage epidemiology approach to estimate drug consumption, in the community from which the wastewater was derived. This back-calculation was updated for the first time to include the concentration of analytes present on SPM. The consumption of methamphetamine and MDMA was determined to be especially high in the studied community in relation to other European countries, while cocaine and methadone consumption was relatively low. This manuscript shows that in order to apply the sewage epidemiology approach, SPM analysis is required for some compounds; whereas for others the partitioning is small and one may regard this as negligible.Highlights► A monitoring study analysing drugs of abuse in both wastewater and suspended particulate matter is reported for the first time. ► Significant proportions of antidepressants (e.g. fluoxetine, 68-80%) were present on the solids. ► The consumption of methamphetamine and MDMA was high in the studied community in the Czech Republic. ► The consumption of cocaine and methadone was relatively low.

Pharmacologically active compounds including both legally used pharmaceuticals and illicit drugs are potent environmental contaminants. Extensive research has been undertaken over the recent years to understand their environmental fate and toxicity. The one very important phenomenon that has been overlooked by environmental researchers studying the fate of pharmacologically active compounds in the environment is their chirality. Chiral drugs can exist in the form of enantiomers, which have similar physicochemical properties but differ in their biological properties such as distribution, metabolism and excretion, as these processes (due to stereospecific interactions of enantiomers with biological systems) usually favour one enantiomer over the other. Additionally, due to different pharmacological activity, enantiomers of chiral drugs can differ in toxicity. Furthermore, degradation of chiral drugs during wastewater treatment and in the environment can be stereoselective and can lead to chiral products of varied toxicity. The distribution of different enantiomers of the same chiral drug in the aquatic environment and biota can also be stereoselective. Biological processes can lead to stereoselective enrichment or depletion of the enantiomeric composition of chiral drugs. As a result the very same drug might reveal different activity and toxicity and this will depend on its origin and exposure to several factors governing its fate in the environment. In this critical review a discussion of the importance of chirality of pharmacologically active compounds in the environmental context is undertaken and suggestions for directions in further research are made. Several groups of chiral drugs of major environmental relevance are discussed and their pharmacological action and disposition in the body is also outlined as it is a key factor in developing a full understanding of their environmental occurrence, fate and toxicity. This review will be of interest to environmental scientists, especially those interested in issues associated with environmental contamination with pharmacologically active compounds and chiral pollutants. As the review will outline current state of knowledge on chiral drugs, it will be of value to anyone interested in the phenomenon of chirality, chiral drugs, their stereoselective disposition in the body and environmental fate (212 references).