Detection, identification and determination of chiral pharmaceutical residues in wastewater: Problems and challenges

Developing an Approach for Integrating Chemical Analysis and Transcriptional Changes to Assess Contaminants in Water, Sediment, and Fish

Pharmaceuticals in aquatic environments pose threats to aquatic organisms because of their continuous release and potential accumulation. Monitoring methods for these contaminants are inadequate, with targeted analyses falling short in assessing water quality's impact on biota. The present study advocates for integrated strategies combining suspect and targeted chemical analyses with molecular biomarker approaches to better understand the risks posed by complex chemical mixtures to nontarget organisms. The research aimed to integrate chemical analysis and transcriptome changes in fathead minnows to prioritize contaminants, assess their effects, and apply this strategy in Wascana Creek, Canada. Analysis revealed higher pharmaceutical concentrations downstream of a wastewater-treatment plant, with clozapine being the most abundant in fathead minnows, showing notable bioavailability from water and sediment sources. Considering the importance of bioaccumulation factor and biota-sediment accumulation factor in risk assessment, these coefficients were calculated based on field data collected during spring, summer, and fall seasons in 2021. Bioaccumulation was classified as very bioaccumulative with values >5000 L kg-1, suggesting the ability of pharmaceuticals to accumulate in aquatic organisms. The study highlighted the intricate relationship between nutrient availability, water quality, and key pathways affected by pharmaceuticals, personal care products, and rubber components. Prioritization of these chemicals was done through suspect analysis, supported by identifying perturbed pathways (specifically signaling and cellular processes) using transcriptomic analysis in exposed fish. This strategy not only aids in environmental risk assessment but also serves as a practical model for other watersheds, streamlining risk-assessment processes to identify environmental hazards and work toward reducing risks from contaminants of emerging concern. Environ Toxicol Chem 2024;00:1-22. © 2024 SETAC.

Ambient ionisation mass spectrometry for drug and toxin analysis: A review of the recent literature

Ambient ionisation mass spectrometry (AIMS) is a form of mass spectrometry whereby analyte ionisation occurs outside of a vacuum source under ambient conditions. This enables the direct analysis of samples in their native state, with little or no sample preparation and without chromatographic separation. The removal of these steps facilitates a much faster analytical process, enabling the direct analysis of samples within minutes if not seconds. Consequently, AIMS has gained rapid popularity across a diverse range of applications, in particular the analysis of drugs and toxins. Numerous fields rely upon mass spectrometry for the detection and identification of drugs, including clinical diagnostics, forensic chemistry, and food safety. However, all of these fields are hindered by the time-consuming and laboratory-confined nature of traditional techniques. As such, the potential for AIMS to resolve these challenges has resulted in a growing interest in ambient ionisation for drug and toxin analysis. Since the early 2000s, forensic science, diagnostic testing, anti-doping, pharmaceuticals, environmental analysis and food safety have all seen a marked increase in AIMS applications, foreshadowing a new future for drug testing. In this review, some of the most promising AIMS techniques for drug analysis will be discussed, alongside different applications of AIMS published over a 5-year period, to provide a summary of the recent research activity for ambient ionisation for drug and toxin analysis.

Advancing chirality analysis through enhanced enantiomer characterization and quantification via fast Fourier transform capacitance voltammetry

The exploration of the chiral configurations of enantiomers represents a highly intriguing realm of scientific inquiry due to the distinct roles played by each enantiomer (D and L) in chemical reactions and their practical utilities. This study introduces a pioneering analytical methodology, termed fast Fourier transform capacitance voltammetry (FFT-CPV), in conjunction with principal component analysis (PCA), for the identification and quantification of the chiral forms of tartaric acid (TA), serving as a representative model system for materials exhibiting pronounced chiral characteristics. The proposed methodology relies on the principle of chirality, wherein the capacitance signal generated by the adsorption of D-TA and L-TA onto the surface of a platinum electrode (Pt-electrode) in an acidic solution is harnessed. The capacitance voltammograms were meticulously recorded under optimized experimental conditions. To compile the final dataset for the analyte, the average of the FFT capacitance voltammograms of the acidic solution (without the presence of the analyte) was subtracted from those containing the analyte. A distinct arrangement was obtained by employing PCA as a linear data transformation method, representing D-TA and L-TA in a two/three-dimensional space. The outcomes of the study reveal the successful detection of the two chiral forms of TA with a considerable degree of precision and reproducibility. Moreover, the proposed method facilitated the establishment of two linear response ranges for the concentration values of each enantiomer, spanning from 1 to 20 µM, and 50 to 500 µM. The respective detection limits were also determined to be 0.4 µM for L-TA and 1.3 µM for D-TA. These findings underscore the satisfactory sensitivity and efficiency of the proposed method in both qualitative and quantitative assessments of the chiral forms of TA.

Role of bio-electrochemical technology for enzyme activity stimulation in high-consumption pharmaceuticals biodegradation

Active pharmaceutical ingredients (APIs) and their intermediate residues have recently been considered a serious concern. Among technologies, bio-electrochemical technologies (BETs) have stimulated the production of bio-electrical energy. This review aims to examine the benefit and mechanism of BETs on the degradation of high-consumption pharmaceutical compounds, including antibiotic, anti-inflammatory, and analgesic drugs, and the stimulation of enzymes induced in a bioreactor. Moreover, intermediates and the proposed pathways of pharmaceutical compound biodegradation in BETs are to be explained in this review. According to studies performed exclusively, the benefit of BETs is using bio-electroactive microbes to mineralize recalcitrant pharmaceutical contaminants by promoting enzyme activity and energy. Since BETs use the electron transfer chain between bio-anode/-cathode and pharmaceuticals, the enzyme activity is essential in the oxidation and reduction of phenolic rings of drugs and the ineffective detoxification of effluent from the treatment plant. This study is suggested a vital and influential role of BETs in mineralizing and enzyme induction in bioreactors. Eventually, a content of future developments or outlooks of BETs are propounded to improve the pharmaceutical industries' wastewater problems.

Hazard and health risk assessment of exposure to pharmaceutical active compounds via toxicological evaluation by zebrafish

The uncontrolled or continuous release of effluents from wastewater treatment plants leads to the omnipresence of pharmaceutical active compounds (PhACs) in the aquatic media. Today, this is a confirmed problem becoming a main subject of twin public and scientific concerns. However, still little information is available about the long-term impacts of these PhACs on aquatic organisms. In this review, efforts were made to reveal correlation between the occurrence in the environment, ecotoxicological and health risks of different PhACs via toxicological evaluation by zebrafish (Danio rerio). This animal model served as a bioindicator for any health impacts after the exposure to these contaminants and to better understand the responses in relation to human diseases. This review paper focused on the calculation of Risk Quotients (RQs) of 34 PhACs based on environmental and ecotoxicological data available in the literature and prediction from the ECOSAR V2.2 software. To the best of the authors' knowledge, this is the first report on the risk assessment of PhACs by the two different methods as mentioned above. RQs showed greater difference in potential environmental risks of the PhACs. These differences in risk values underline the importance of environmental and experimental factors in exposure conditions and the interpretation of RQ values. While the results showed high risk to Danio rerio of the majority of PhACs, risk qualification of the others varied between moderate to insignifiant. Further research is needed to assess pharmaceutical hazards when present in wastewater before discharge and monitor the effectiveness of treatment processes. The recent new advances in the morphological assessment of toxicant-exposed zebrafish larvae for the determination of test compounds effects on the developmental endpoints were also discussed. This review emphasizes the need for strict regulations on the release of PhACs into environmental media in order to minimize their toxicity to aquatic organisms.

β-Cyclodextrin functionalized adsorbents for removal of organic micropollutants from water

The presence of organic micropollutants in water is an ongoing concern due to the potential risks to living organisms. β-Cyclodextrin-based adsorbents have been developed to remove organic micropollutants from water as they are deemed to be efficient, selective and reusable. This literature review establishes the current state of the knowledge on the application of β-Cyclodextrin adsorbents for the removal of organic micropollutants from water and determines knowledge gaps and recommendations for future studies. An inventory of organic micropollutants that have been studied was developed and it revealed that bisphenol-A has been the most commonly studied. Adsorbent configurations were reviewed and modifications to the adsorbent structures that have provided enhanced adsorption properties were identified. The size and shape of the organic micropollutants was found to affect the adsorption behavior. The surface charge of β-Cyclodextrin adsorbents influence adsorption when repulsive forces are present and the extent of repulsion can depend on the pH of the solution. Common competitors such as natural organic matter and inorganic ions do not significantly impact the adsorption of organic micropollutants however relatively small fulvic acids may compete for the β-Cyclodextrin cavity depending on the adsorbent type. Desorption of organic micropollutants from these adsorbents has been accomplished with alcohols and most adsorbents have been recovered and reused in adsorption/desorption cycles. The need for enhanced recovery processes that maintain water quality and adsorbent integrity was identified. The use of quantitative structure-activity relationships and molecular computational tools could potentially guide future environmental applications of β-Cyclodextrin adsorbents.

Effect of additional Fe2+ salt on electrocoagulation process for the degradation of methyl orange dye: An optimization and kinetic study

The wastewater generated from textile industries is highly colored and contains dyes including azo dyes, which are toxic to human and water-living organisms. The treatment of these azo dyes using conventional treatment techniques is challenging due to their recalcitrant properties. In the current study, the effect of additional Fe²⁺ on electrocoagulation (EC) using Fe electrodes has been studied for the removal of methyl orange (MO) azo dye. pH between 4-5 was found to be optimum for EC and treatment efficiency decreased with increasing dye concentrations. With the addition of Fe²⁺ salt, dye removal for a certain concentration was increased with the increase of current density and Fe²⁺ up to a certain limit and after that, the removal efficiency decreased. The COD, color and dye removals were 88.5%, 93.1% and 100%, respectively, for EC of 200 mg.L⁻¹ dye solution using only 0.20 mmol.L⁻¹ Fe²⁺ for 0.40 mA cm⁻² current density, whereas for EC, the respective removal efficiencies were 76.7%, 63.4% and 82.4% for 32 min. The respective operating cost for EC was $768 kg⁻¹ removed dye ($0.342 m⁻³), whereas, for EC with additional Fe²⁺ salt, it was $350 kg⁻¹ removed dye ($0.189 m⁻³). The kinetic results revealed that the first-order kinetic model was fitted best for EC, whereas the second-order kinetic model was best fitted for Fe²⁺ added EC. For real textile wastewater, 57.6% COD removal was obtained for 0.15 mmol.L⁻¹ Fe²⁺ added EC compared to 27.8% COD removal for EC for 32 min. Based on the study we can conclude that Fe²⁺ assisted EC can be used for effective treatment of textile wastewater containing toxic compounds like azo dyes.

•

EC represents limiting treatment performance for higher contaminant concentrations.

•

0.20 mmol.L⁻¹ Fe²⁺ salt enhances the EC treatment performance of MO dye to 100%.

•

EC followed first-order kinetic model, whereas Fe²⁺ added EC followed second-order kinetic model.

•

Operating cost was reduced to $0.327 m⁻³ from $0.598 m⁻³ for EC with additional Fe²⁺.

•

58% COD was removed for 0.15 mmol.L⁻¹ Fe²⁺ added EC for real textile wastewater.

Detection and remediation of chiral pharmaceuticals from wastewater: A review

Chiral organic pollutants including pharmaceuticals, pesticides, herbicides, flame retardants, and polycyclic musk cause significant risks to both the environment and human health. Chiral pharmaceuticals (CPs) are among the significant class of pseudo-persistent substances that have been observed in the concentration level from nanomolar to micromolar quantities and cause bad impacts on nontargeted species and direct or indirect human health issues due to water and foodborne contamination. The CPs may contain one or more chiral centers in their structural framework and thus enantiomers of CPs often possess different distribution, fate, bioaccumulation potential, and toxicity. The enantioselective chromatographic techniques have been extensively applied to detect drug enantiomers during the last few years. Bioremediation techniques offer unique characteristics above conventional remediation procedures as these could be cost-effective and accomplish total organic pollutant decomposition without causing collateral damage to the site material or native flora and fauna. This review describes the impacts of chiral pharmaceuticals on the environment; detection technologies (particularly liquid chromatography), and important remedial measures for safer disposal of such pollutants.

Gut Microbiota Composition in Relation to the Metabolism of Oral Administrated Resveratrol

Resveratrol (RSV) has been confirmed to confer multiple health benefits, and the majority of RSV tends to be metabolized in the gut microbiota after oral administration. In this study, the metabolism of RSV was investigated by using mouse models with distinct gut microbiota compositions: germ-free mice colonized with probiotics, conventional mouse, and DSS-induced colitis mouse models. The results demonstrated that in feces, the metabolites of RSV, including resveratrol sulfate (RES-sulfate), resveratrol glucuronide (RES-glucuronide), and dihydroresveratrol, significantly increased after probiotics colonized in germ-free mice. Furthermore, RES-sulfate and RES-glucuronide were below the detectable limit in the feces of conventional mice, with dihydroresveratrol being the dominant metabolite. Compared to the conventional mice, the ratio of Firmicutes/Bacteroides and the abundance of Lactobacillus genera were found significantly elevated in colitis mice after long-term ingestion of RSV, which shifted the metabolism of RSV in return. Our study provided critical implications in further application of RSV in foods and food supplements.

Chiral inversion of 2-arylpropionoic acid (2-APA) enantiomers during simulated biological wastewater treatment

This study examined the removal and enantio‑specific fate of a suite of eleven chiral 2-arylpropionic acids (2-APAs) during biological wastewater treatment simulated in a laboratory-scale membrane bioreactor (MBR). Using pure (R)- and (S)- enantiomers in the MBR influent, chiral inversion was determined through the increase in the concentration of the non-dominant enantiomer and changes in the enantiomeric fraction (EF) between the two enantiomers during the treatment process. Effective (>90%) and similar removal rates between (R)- and (S)- enantiomers were confirmed for eight 2-APAs. In this study, 2-APAs exhibited diverse and distinctive chiral inversion behaviours: two 2-APAs showed (R→S) unidirectional inversion, three 2-APAs showed (S→R) unidirectional inversion, and six 2-APAs showed bidirectional inversion. This is the first study to report chiral inversion behaviours of a comprehensive suite of 2-APAs with a variety of functional groups substituted onto the aryl ring. A decrease in effluent EF over time was observed for two 2-APAs. This study shows that chiral inversion of 2-APAs varies significantly from compound to compound, despite the high similarity in their chemical structures.

Identification of biomarkers in wastewater-based epidemiology: Main approaches and analytical methods

Wastewater-based epidemiology (WBE) has become popular to estimate the use of drugs of abuse and recently to establish the incidence of CoVID 19 in large cities. However, its possibilities have been expanded recently as a technique that allows to establish a fingerprint of the characteristics of a city, such as state of health/disease, healthy/unhealthy living habits, exposure to different types of contaminants, etc. with respect to other cities. This has been thanks to the identification of human biomarkers as well as to the fingerprinting and profiling of the characteristics of the wastewater catchment that determine these circumstances. The purpose of this review is to analyze the different methodological schemes that have been developed to perform this biomarker identification as well as the most characteristic analytical techniques in each scheme, their advantages and disadvantages and the knowledge gaps identified. We also discussed the future scope for development.

Predicting the trend and utility of different photocatalysts for degradation of pharmaceutically active compounds: A special emphasis on photocatalytic materials, modifications, and performance comparison

The rapid rise in the healthcare sector has led to an increase in pharmaceutically active compounds (PhACs) in different aqueous bodies. The toxicity of the PhACs and their ability to persist after conventional treatment processes have escalated research in the field of photocatalytic treatment. Although different photocatalysts have been successful in degrading PhACs, their inherent drawbacks have severely limited their application on a large scale. A substantial amount of research has been aimed at overcoming the high cost of the photocatalytic material, low quantum yield, the formation of toxic end products, etc. Hence, to further research in this field, researchers must have a fair idea of the current trends in the application of different photocatalysts. In this article, the trends in the use of various photocatalysts for the removal of different PhACs have been circumscribed. The performance of different groups of photocatalysts to degrade PhACs from synthetic and real wastewater has been addressed. The drawbacks and advantages of these materials have been compared, and their future in the field of PhACs removal has been predicted using S-curve analysis. Zinc and titanium-based photocatalysts were efficient under UV irradiation, while bismuth and graphene-based materials exhibited exemplary performance in visible light. However, iron-based compounds were found to have the most promising future, which may be because of their magnetic properties, easy availability, low bandgap, etc. Different modification techniques, such as morphology modification, doping, heterojunction formation, etc., have also been discussed. This study may help researchers to clarify the current research status in the field of photocatalytic treatment of PhACs and provide valuable information for future research.

Biodegradation of Emerging Pharmaceuticals from Domestic Wastewater by Membrane Bioreactor: The Effect of Solid Retention Time

Although conventional biological treatment plants can remove basic pollutants, they are ineffective at removing recalcitrant pollutants. Membrane bioreactors contain promising technology and have the advantages of better effluent quality and lower sludge production compared to those of conventional biological treatment processes. In this study, the removal of pharmaceutical compounds by membrane bioreactors under different solid retention times (SRTs) was investigated. To study the effect of SRT on the removal of emerging pharmaceuticals, the levels of pharmaceuticals were measured over 96 days for the following retention times: 20, 30, and 40-day SRT. It was found that the 40-day SRT had the optimum performance in terms of the pharmaceuticals’ elimination. The removal efficiencies of the chemical oxygen demand (COD) for each selected SRT were higher than 96% at steady-state conditions. The highest degradation efficiency was observed for paracetamol. Paracetamol was the most removed compound followed by ranitidine, atenolol, bezafibrate, diclofenac, and carbamazepine. The microbial community at the phylum level was also analyzed to understand the biodegradability of pharmaceuticals. It was noticed that the Proteobacteria phylum increased from 46.8% to 60.0% after 96 days with the pharmaceuticals. The Actinobacteria class, which can metabolize paracetamol, carbamazepine, and atenolol, was also increased from 9.1% to 17.9% after adding pharmaceuticals. The by-products of diclofenac, bezafibrate, and carbamazepine were observed in the effluent samples.

Chiral Recognition for Chromatography and Membrane-Based Separations: Recent Developments and Future Prospects

With the rapid development of global industry and increasingly frequent product circulation, the separation and detection of chiral drugs/pesticides are becoming increasingly important. The chiral nature of substances can result in harm to the human body, and the selective endocrine-disrupting effect of drug enantiomers is caused by differential enantiospecific binding to receptors. This review is devoted to the specific recognition and resolution of chiral molecules by chromatography and membrane-based enantioseparation techniques. Chromatographic enantiomer separations with chiral stationary phase (CSP)-based columns and membrane-based enantiomer filtration are detailed. In addition, the unique properties of these chiral resolution methods have been summarized for practical applications in the chemistry, environment, biology, medicine, and food industries. We further discussed the recognition mechanism in analytical enantioseparations and analyzed recent developments and future prospects of chromatographic and membrane-based enantioseparations.

Determination of Pharmaceutical Residues by UPLC-MS/MS Method: Validation and Application on Surface Water and Hospital Wastewater

In this study, an analytical method for the simultaneous determination of 7 major pharmaceutical residues in Vietnam, namely, carbamazepine, ciprofloxacin, ofloxacin, ketoprofen, paracetamol, sulfamethoxazole, and trimethoprim, in surface water and hospital wastewater has been developed. The method includes enrichment and clean-up steps by solid phase extraction using mix-mode cation exchange, followed by identification and quantification using an ultrahigh-performance liquid chromatography and tandem mass spectrometry and employing electrospray ionization (UPLC-ESI-MS/MS). Seven target compounds were separated on the reversed phase column and detected in multiple reaction monitoring (MRM) mode within 6 minutes. The present study also optimized the operating parameters of the mass spectrometer to achieve the highest analytical signals for all target compounds. All characteristic parameters of the analytical method were investigated, including linearity range, limit of detection, limit of quantification, precision, and accuracy. The important parameter in UPLC-ESI-MS/MS, matrix effect, was assessed and implemented via preextraction and postextraction spiking experiments. The overall recoveries of all target compounds were in the ranges from 55% to 109% and 56 % to 115% for surface water and hospital wastewater, respectively. Detection limits for surface water and hospital wastewater were 0.005-0.015 µg L^-1 and 0.014-0.123 µg L^-1, respectively. The sensitivity of the developed method was allowed for determination of target compounds at trace level in environmental water samples. The in-house validation of the developed method was performed by spiking experiment in both the surface water and hospital wastewater matrix. The method was then applied to analyze several surface water and hospital wastewater samples taken from West Lake and some hospitals in Vietnam, where the level of these pharmaceutical product residues was still missed. Sulfamethoxazole was present at a high detection frequency in both surface water (33% of analyzed samples) and hospital wastewater (81% of analyzed samples) samples.

A comprehensive review on contaminants removal from pharmaceutical wastewater by electrocoagulation process

The pharmaceuticals are emergent contaminants, which can create potential threats for human health and the environment. All the pharmaceutical contaminants are becoming enormous in the environment as conventional wastewater treatment cannot be effectively implemented due to toxic and intractable action of pharmaceuticals. For this reason, the existence of pharmaceutical contaminants has brought great awareness, causing significant concern on their transformation, occurrence, risk, and fate in the environments. Electrocoagulation (EC) treatment process is effectively applied for the removal of contaminants, radionuclides, pesticides, and also harmful microorganisms. During the EC process, an electric current is employed directly, and both electrodes are dissoluted partially in the reactor under the special conditions. This electrode dissolution produces the increased concentration of cation, which is finally precipitated as hydroxides and oxides. Different anode materials usage like aluminum, stainless steel, iron, etc. are found more effective in EC operation for efficient removal of pharmaceutical contaminants. Due to the simple procedure and less costly material, EC method is extensively recognized for pharmaceutical wastewater treatment over further conventional treatment methods. The EC process has more usefulness to destabilize the pharmaceutical contaminants with the neutralization of charge and after that coagulating those contaminants to produce flocs. Thus, the review places particular emphasis on the application of EC process to remove pharmaceutical contaminants. First, the operational parameters influencing EC efficiency with the electroanalysis techniques are described. Second, in this review emerging challenges, current developments and techno-economic concerns of EC are highlighted. Finally, future recommendations and prospective on EC are envisioned.

Green Approaches to Sample Preparation Based on Extraction Techniques

Preparing a sample for analysis is a crucial step of many analytical procedures. The goal of sample preparation is to provide a representative, homogenous sample that is free of interferences and compatible with the intended analytical method. Green approaches to sample preparation require that the consumption of hazardous organic solvents and energy be minimized or even eliminated in the analytical process. While no sample preparation is clearly the most environmentally friendly approach, complete elimination of this step is not always practical. In such cases, the extraction techniques which use low amounts of solvents or no solvents are considered ideal alternatives. This paper presents an overview of green extraction procedures and sample preparation methodologies, briefly introduces their theoretical principles, and describes the recent developments in food, pharmaceutical, environmental and bioanalytical chemistry applications.