Determination of nine pharmaceutical active compounds in surface waters from Paraopeba River Basin in Brazil by LTPE-HPLC-ESI-MS/MS

Protecting the Last Line of Defense: Analytical Approaches for Sample Preparation and Determination of the Reserve Group of Antibiotics in the Environment

Drug resistance in microorganisms is a serious threat to life and health due to the limited number of antibiotics that show efficacy in treating infections and the difficulty in discovering new compounds with antibacterial activity. To address this issue, the World Health Organization created the AWaRe classification, a tool to support global and national antimicrobial stewardship programs. The AWaRe list categorizes antimicrobials into three groups - Access, Watch, and Reserve - according to their intended use. The Reserve group comprises "last resort" medicines used solely for treating infections caused by bacterial strains that are resistant to other treatments. It is therefore necessary to protect them, not only by using them as prudently as possible in humans and animals, but also by monitoring their subsequent fate. Unmetabolized antibiotics enter the environment through hospital and municipal wastewater or from manure, subsequently contaminating bodies of water and soils, thus contributing to the emergence and spread of antibiotic resistance. This article presents a review of determination methods for the Reserve group of antimicrobials in water, wastewater, and manure. Procedures for extracting and determining these substances in environmental samples are described, showing the limited research available, which is typically on a local level.

Antifungal drugs in the aquatic environment: A review on sources, occurrence, toxicity, health effects, removal strategies and future challenges

Fungal infections pose a significant global health burden, resulting in millions of severe cases and deaths annually. The escalating demand for effective antifungal treatments has led to a rise in the wholesale distribution of antifungal drugs, which consequently has led to their release into the environment, posing a threat to ecosystems and human health. This article aims to provide a comprehensive review of the presence and distribution of antifungal drugs in the environment, evaluate their potential ecological and health risks, and assess current methods for their removal. Reviewed studies from 2010 to 2023 period have revealed the widespread occurrence of 19 various antifungals in natural waters and other matrices at alarmingly high concentrations. Due to the inefficiency of conventional water treatment in removing these compounds, advanced oxidation processes, membrane filtration, and adsorption techniques have been developed as promising decontamination methods.In conclusion, this review emphasizes the urgent need for a comprehensive understanding of the presence, fate, and removal of antifungal drugs in the environment. By addressing the current knowledge gaps and exploring future prospects, this study contributes to the development of strategies for mitigating the environmental impact of antifungal drugs and protecting ecosystems and human health.

Selected widely prescribed pharmaceuticals: toxicity of the drugs and the products of their photochemical degradation to aquatic organisms

Cholesterol-lowering drugs, antidiabetics, antiarrhythmics, antidepressants, and antibiotics belong to the most prescribed drugs worldwide. Because of the manufacture, excretion, and improper disposal of leftover drugs, the drugs enter waste waters and, subsequently, surface waters. They have been detected in surface waters all over the world, from concentrations of ng/l to concentrations several orders of magnitude higher. Since pharmaceuticals are designed to be both biologically and chemically stable, photochemical degradation by sun radiation represents a way of transformation in the natural environment. This review provides a survey of how selected drugs of the above-mentioned classes affect aquatic organisms of different trophic level. The emphasis is on the harmful effects of phototransformation products, an area of scientific investigation that has only attracted attention in the past few years, revealing the surprising fact that products of photochemical degradation might be even more toxic to aquatic organisms than the parent drugs.

Pharmaceutically active compounds (PhACs) in surface water: Occurrence, trends and risk assessment in the Tagus River Basin (Spain)

In this study, the presence of 23 pharmaceutically active compounds (PhACs) including antibiotics, analgesics, anti-inflammatories, psychiatric and cardiovascular drugs, antifungals and metabolites was investigated in surface waters. A total of 89 samples were collected during 3 years (2020, 2021 and 2022) from a European representative river basin (Tagus, Spain). To elucidate PhAC potential sources, sampling points located in areas with low, median and high anthropogenic influence were selected. The analytical method based on solid phase extraction (SPE) followed by UHPLC-MS/MS analysis was validated meeting SANTE/2020/12830 and SANTE/12682/2019 performance criteria. PhACs were quantified above limits of quantification (LOQs) in 96 % of water samples, being the antihypertensives valsartan (648 ng/L, 87 % quantification frequency) and irbesartan (390 ng/L, 75 %) and the antidepressant o-desmethylvenlafaxine (495 ng/L, 76 %) the predominant pollutants. The rest of the target PhACs showed median concentrations between 4 and 172 ng/L with quantification frequencies ranging from 35 to 75 %. ∑PhAC concentrations did not show temporal or seasonal trends. However, valsartan and naproxen presented lower levels in drier (spring and summer) compared to the wetter. Source identification revealed a clear anthropogenic origin since concentrations obtained in highly populated areas were statistically higher (p < 0.01) than those quantified in sparsely populated ones. This finding was also confirmed by calculating PhACs mass flow rates, which ranged between 1.4 and 235 kg/y. Finally, data generated were used to estimate the potential risk to the aquatic ecosystem for three trophic levels (phototrophic, invertebrate and vertebrate organisms). Risk quotient ratios (RQs) were calculated for all PhACs at the median (P50) and worst-case (max) scenarios. Up to 7 PhACs (acetaminophen, carbamazepine, gemfibrozil, ibuprofen, irbesartan, ketoprofen and venlafaxine) showed high risk for the highest trophic level (fish) in >45 % of investigated locations.

Dynamics of drug contamination of the river-water in the rural, semirural and urban areas of the Mrežnica River in Croatia during COVID-19 pandemic (2020-2021)

Increased contamination of aquatic ecosystems with pharmaceuticals could have been expected due to the COVID-19 pandemic. Surface water from three domains (rural, semirural, urban) of the Mrežnica River (Croatia) was screened for 253 pharmaceuticals by SPE-UHPLC-MS/MS. At the beginning of the pandemic, the highest concentration of drugs (excluding veterinary) was detected at urban site (291.4 ng/L), followed by semirural (186.5 ng/L) and rural (141.6 ng/L). With the progression of pandemic, contamination increase was observed at all sites, but it was the most obvious at semirural (approximately 400-700 ng/L). The most pronounced concentration increases were observed for non-opioid analgesics, especially ibuprofen. In September 2021, the first notable occurrence of opioid analgesics was recorded. The most represented group of pharmaceuticals at the start of the pandemic (May 2020) was generally stimulants (caffeine, cotinine). In September 2021, the predominant group was analgesics at all sites (45-84%), whereas stimulants decreased to undetectable levels. The results of this study indicated that the epidemiological measures and medical treatments that were widely imposed/applied caused notable increase of the surface water contamination with drugs of a small river with limited dilution capacity, indirectly pointing to the changes that occurred in the behaviour and habits of the inhabitants of the affected areas.

Analytical Methodologies for the Estimation of Oxazolidinone Antibiotics as Key Members of anti-MRSA Arsenal: A Decade in Review

Gram-positive bacterial infections are among the most serious diseases related with high mortality rates and huge healthcare costs especially with the rise of antibiotic-resistant strains that limits treatment options. Thus, development of new antibiotics combating these multi-drug resistant bacteria is crucial. Oxazolidinone antibiotics are the only totally synthetic group of antibiotics that showed activity against multi-drug resistant Gram positive bacteria including MRSA because of their unique mechanism of action in targeting protein synthesis. This group include approved marketed members (tedizolid, linezolid and contezolid) or those under development (delpazlolid, radezolid and sutezolid). Due to the significant impact of this class, larger number of analytical methods were required to meet the needs of both clinical and industrial studies. Analyzing these drugs either alone or with other antimicrobial agents commonly used in ICU, in the presence of pharmaceutical or endogenous biological interferences, or in the presence of matrix impurities as metabolites and degradation products poses a big analytical challenge. This review highlights current analytical approaches published in the last decade (2012-2022) that dealt with the determination of these drugs in different matrices and discusses their advantages and disadvantages. Various techniques have been described for their determination including chromatographic, spectroscopic, capillary electrophoretic and electroanalytical methods. The review comprises six sections (one for each drug) with their related tables that depict critical figures of merit and some experimental conditions for the reviewed methods. Furthermore, future perspectives about the analytical methodologies that can be developed in the near future for determination of these drugs are suggested.

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.

The presence of antibiotics and multidrug-resistant Staphylococcus aureus reservoir in a low-order stream spring in central Brazil

The disposal of industrial effluents strongly influences low-order streams, which makes them fragile ecosystems that can be impacted by contamination. In central Brazil, the Extrema River spring targets the dumping of pharmaceutical products from the surrounding industries. So, this work aimed to investigate the presence of antibiotics in Extrema River spring samples and the isolation of Staphylococcus aureus, a potential multidrug-resistant bacteria, verifying the antimicrobial resistance profile of these isolates. Three campaigns were carried out in different locals (P1-P3) between October and December 2021, in the dry and rainy seasons. The high-performance liquid chromatography-tandem mass spectrometry (LCMS) approach indicated the presence of sulfamethoxazole (≥ 1 ng/L), metronidazole (< 0.5 ng/L), and chloramphenicol (< 5 ng/L) in the water samples in November (rainy season). S. aureus was isolated in P1 (n = 128), P2 (n = 168), and P3 (n = 36), with greater resistance to trimethoprim-sulfamethoxazole (90%), clindamycin (70%), and gentamicin (60%). The presence of antibiotics in the Extrema River spring may cause S. aureus antibiotic resistance development. The presence of antibiotics and the high percentage of isolated multidrug-resistant S. aureus in the Extrema River spring cause concern and indicate the clandestine dumping of effluents from nearby pharmaceutical industries. Since preserving the springs of low-order streams is important for the environment and public health, we encourage monitoring the wastewater from Extrema River's nearby pharmaceutical industries and preserving the spring of this river.

Emerging contaminants in the aquatic environment: phytoplankton structure in the presence of sulfamethoxazole and diclofenac

Chemicals from anthropogenic activities such as domestic sewage, pesticide leaching, and improper chemical disposal have caused groundwater contamination. The presence of these emerging contaminants in the aquatic environment can change water quality and biota composition. Thus, this study investigates the effect of two emerging contaminants, anti-inflammatory drug diclofenac (DCF) and antibiotic sulfamethoxazole (SMX), on the aquatic environment, evaluating the phytoplankton community structure. A microcosm experiment was conducted with 16 sampling units, each one with 500 mL of water sample containing phytoplankton exposed to these drugs at different concentrations (0.1, 0.5, and 1.0 mg L-1). The experiment lasted 15 days, and samples were collected on days 0, 3, 5, 7, and 14 to evaluate the phytoplankton community, the concentrations of the drugs, and the nutrients in the samples. Six phytoplankton groups were identified, and diatoms and green algae were the most diverse and abundant groups. For the entire community, we identified differences between the days of the experiment, varying in the diversity and density of organisms, but not between the concentrations of the two drugs. Evaluating the groups separately, we identified differences in the abundance of cyanobacteria for the treatment with diclofenac and desmids for the treatment with sulfamethoxazole. We demonstrated that the presence of pharmaceuticals in freshwater ecosystems can somehow affect the phytoplankton community, especially the diversity and abundance of cyanobacteria and desmids. Therefore, our study indicates the importance of evaluating the presence of pharmaceuticals in freshwater ecosystems and their influence on aquatic organisms, as well as pharmaceuticals may be changing the structure of the aquatic environment.

Occurrence and removal of drugs and endocrine disruptors in water supply systems in the metropolitan region of Belo Horizonte (Minas Gerais State, Brazil)

This study evaluates both the occurrence and removal of 24 compounds, including drugs and endocrine disruptors, in 8 water treatment plants (WTP) located in the metropolitan region of Belo Horizonte (Minas Gerais State, Brazil). The compounds 4-nonylphenol, 4-octylphenol, 17α-ethinylestradiol, 17β-estradiol, acyclovir, bisphenol A, bezafibrate, caffeine, dexamethasone, diclofenac sodium, diltiazem, estrone, estriol, gemfibrozil, ibuprofen, linezolid, loratadine, losartan, metformin, naproxen, paracetamol, promethazine, propranolol and sulfamethoxazole were monitored at 3 sampling points (raw water, filtered water, treated water) over 10 or 12 collection campaigns for each WTP. The results showed that bisphenol A occurred at higher concentrations during the dry period with a maximum concentration of 3257.1 ng L^-1, while the compounds 4-nonylphenol and losartan exhibited higher concentrations in the rainy period with maximum concentrations of 8577.2 ng L^-1 and 705.8 ng L^-1, respectively. Regarding the removal of compounds in the monitored WTPs, the clarification step demonstrated better removals for 4-nonylphenol, bisphenol-A, paracetamol, and sulfamethoxazole, whereas the disinfection step mainly removed the compounds 4-octylphenol and estrone. Margin of exposure (ME) assessment results indicated that only dexamethasone, ethinyl estradiol, diclofenac, estradiol, and estrone were classified as imminent risk or alert considering the 95th percentile concentration found in the samples of treated water.

Emerging contaminants in Brazilian aquatic environment: identifying targets of potential concern based on occurrence and ecological risk

Although studies have shown the presence of Contaminants of Emerging Concern (CECs) in the Brazilian environment in recent decades, several biological effects on the aquatic ecosystem are unknown. Brazil is the fifth largest country in extension in the world, and its wide territory presents geographic regions with diverse demographic and economic characteristics. In order to identify targets of potential concern based on occurrence and ecological risk, available data from previous studies were examined to conduct environmental risk analysis and provide a ranking of CECs in Brazilian aquatic environment based on environmental concentration measured in the last 10 years. The results indicate that 17α-ethynylestradiol, 17ß-estradiol, acetaminophen, Bisphenol A, caffeine, diclofenac, ibuprofen, methylparaben, sulfamethoxazole and triclosan are the CECs that represent the greatest threats to the Brazilian environment. Therefore, these contaminants should be considered as a priority in future monitoring studies. Besides, identification of target monitoring compounds can facilitate the selection of pollutant candidates in future legislations.

Pharmaceuticals, pesticides and metals/metalloids in Lake Guaíba in Southern Brazil: Spatial and temporal evaluation and a chemometrics approach

Compiling and reporting data related to the presence of pharmaceuticals and pesticides are crucial means of assessing the risk those chemicals pose to human health and environment. Data sets from different sources were combined using a data fusion approach to produce a spatial and temporal variation of contaminants presents in water from Lake Guaíba (29°55'-30°24' S; 51°01'-51°20' W). Lake Guaíba is a 496 km² water body situated in the geological depression of Rio Grande do Sul State, Brazil; that is fed by several rivers from the metropolitan area, the 5th largest metro area in Brazil, with approximately 5 million inhabitants. Analytical methodology to quantify pharmaceuticals and pesticides by LC-QTOF-MS and GC-MS/MS was validated for 41 pharmaceutical and 62 pesticides. Furthermore, 27 chemical elements were analyzed by ICP-MS, and physical chemical parameters were determined using established methodologies. All validation parameters were in accordance with the National Institute of Metrology, Standardization, and Industrial Quality. Thirty-five water samples were analyzed from January to August 2019, and 15 pharmaceuticals and 25 pesticides were present in concentrations ranging from 6.00 ng L^-1 to 580.00 ng L^-1. Twenty-seven elements were analyzed during the same period, and 18 were present in concentrations ranging from 0.2 μg L^-1 to 7060 μg L^-1. Samples were tagged according to the points and months of collection to identify temporal and spatial patterns. The main findings show that the compounds are distributed throughout the studied area without an apparent regular pattern, suggesting that events in a specific point affect the entire ecosystem. Conversely, temporal variations were well defined, as samples were grouped according to the climatic conditions of the months of collection. Considering the calculated quotient risks, atrazine, cyproconazole, diuron, and simazine showed the highest risk levels for algae; acetaminophen, diclofenac, and ibuprofen showed the highest risk levels for aquatics invertebrates.

Oxazolidinone Antibiotics: Chemical, Biological and Analytical Aspects

This review covers the main aspects concerning the chemistry, the biological activity and the analytical determination of oxazolidinones, the only new class of synthetic antibiotics advanced in clinical use over the past 50 years. They are characterized by a chemical structure including the oxazolidone ring with the S configuration of substituent at C5, the acylaminomethyl group linked to C5 and the N-aryl substituent. The synthesis of oxazolidinones has gained increasing interest due to their unique mechanism of action that assures high antibiotic efficiency and low susceptibility to resistance mechanisms. Here, the main features of oxazolidinone antibiotics licensed or under development, such as Linezolid, Sutezolid, Eperezolid, Radezolid, Contezolid, Posizolid, Tedizolid, Delpazolid and TBI-223, are discussed. As they are protein synthesis inhibitors active against a wide spectrum of multidrug-resistant Gram-positive bacteria, their biological activity is carefully analyzed, together with the drug delivery systems recently developed to overcome the poor oxazolidinone water solubility. Finally, the most employed analytical techniques for oxazolidinone determination in different matrices, such as biological fluids, tissues, drugs and natural waters, are reviewed. Most are based on HPLC (High Performance Liquid Chromatography) coupled with UV-Vis or mass spectrometer detectors, but, to a lesser extent are also based on spectrofluorimetry or voltammetry.

Occurrence of contaminants of emerging concern in surface waters from Paraopeba River Basin in Brazil: seasonal changes and risk assessment

This study describes the application of gas chromatography coupled to mass spectrometry (GC-MS) to evaluate the occurrence of 12 CECs-contaminants of emerging concern (bisphenol A, diclofenac, 17β-estradiol, estriol, estrone, 17α-ethinylestradiol, gemfibrozil, ibuprofen, naproxen, 4-nonylphenol, 4-octylphenol, and acetaminophen) in surface waters from Paraopeba River Basin, Minas Gerais State, Brazil. The analytical procedure was validated and applied to 60 surface water samples collected across four sampling campaigns along the upper and middle watershed. Methods for CECs determination involved sample filtration, and solid-phase extraction (SPE) with subsequent derivatization of the target compounds prior to their analysis by GC-MS. The LOQ varied from 3.6 to 14.4 ng/L and extraction recoveries ranged from 46.1 to 107.1% for the lowest spiked concentration level (10 ng/L). The results showed a profile of spatial distribution of compounds, as well as the influence of rainfall. Ibuprofen (1683.9 ng/L), bisphenol (1587.7 ng/L), and naproxen (938.4 ng/L) occurred in higher concentrations during the rainy season, whereas during the dry season, the concentrations of bisphenol (1057.7 ng/L), estriol (991.0 ng/L), and estrone (978.4 ng/L) were highlighted. The risk assessment of human exposure shows that for most contaminants, the concentration is well below the estimated thresholds for chronic toxicity from water intake. However, estradiol and 17α-ethinylestradiol showed concentrations in the same order of magnitude as the guide values estimated for babies.

Low-temperature partitioning extraction followed by liquid chromatography tandem mass spectrometry determination of multiclass antibiotics in solid and soluble wastewater fractions

An analytical method based on low-temperature partitioning extraction (LTPE) followed by high performance liquid chromatography coupled to triple quadrupole mass spectrometry analysis was developed and validated for the determination of eight multiclass antibiotics in wastewater. The analyzed target antibiotics included one β-lactam, two sulfonamides, three fluoroquinolones, one macrolide and one diaminopyrimidine. LTPE parameters such as sample pH, volume ratio between sample and extractor solvent, ultra-sonic extraction time, extraction tube material, solvent and volume to reconstitute the sample extracts, were optimized. Additionally, the influence of solids on extraction efficiency was evaluated. Quantification of the target antibiotics was performed by double consecutive injection method, without the use of a labeled compound, in order to correct matrix effects. The whole samples were analyzed, including, liquid and solid fractions of wastewater. The results revealed that the filtration step can underestimate the total antibiotics concentration, particularly to the hydrophobic compounds that have higher affinity for solids, indicating that the suspended wastewater particulate should not be neglected. The method detection limit ranged from 18.54 ng L^-1 (trimethoprim) to 78.49 ng L^-1 (ciprofloxacin). Intra-day precision of less than 12.3% was achieved. The recoveries values ranged from 13.9% (sulfadiazine) to 48.9% (erythromycin) in influent samples and from 19.1% (sulfadiazine) to 57.2% (ciprofloxacin) in effluent samples. The method was applied to the measurement of antibiotic residues in influent and effluent from wastewater treatment plants. The majority target antibiotics were detected in wastewater samples. Their concentrations ranged from 237 to 9553 ng L^-1 in influent and from 212 to 1660 ng L^-1 in effluent. This work provides new insights on the applicability of LTPE for antibiotic residues extraction from wastewater. In addition, the performed analysis highlights the importance of measuring total concentrations of analytes in whole sample.

Determination of DDT in honey samples by liquid-liquid extraction with low-temperature purification (LLE-LTP) combined to HPLC-DAD

Honey is widely consumed worldwide, however, this food can be contaminated by chemical contaminants, such as the insecticide dichlorodiphenyltrichloroethane (DDT). Despite legal restrictions on DDT use, this organochlorine pesticide has been detected in honey collected in several developed and developing countries, representing risks to human health, animals, and the environment due to its high environmental persistence, potential carcinogenicity, and ecotoxicological effects. Thus, the development of an analytical method for DDT monitoring in this matrix is important to ensure food security. Therefore, this study aimed to optimize and validate a simple, low-cost, and efficient method using the liquid-liquid extraction with low-temperature purification (LLE-LTP) to determine DDT in honey samples by high-performance liquid chromatography with diode array detector (HPLC-DAD). The proposed method was validated according to SANTE guidelines, being considered selective, precise, accurate, and linear in the range of 8.0-160 μg kg^-1. The limits of detection (LOD) and quantification (LOQ) achieved were 4.0 and 8.0 μg kg^-1, respectively. This LOQ value is lower than the maximum residue limit established by the Brazilian and European Union legislation. Therefore, the LLE-LTP combined to HPLC-DAD allows the routine analysis of DDT in honey samples and can be widely applied in studies to monitor this pesticide, especially in developing countries, where DDT use is still allowed.

Method development for simultaneous determination of polar and nonpolar pesticides in surface water by low-temperature partitioning extraction (LTPE) followed by HPLC-ESI-MS/MS

During this research, chemometric approaches were applied for optimization of the low-temperature partitioning extraction (LTPE) for the simultaneous analysis of the pesticides: acephate, difenoconazole, fenamidone, fluazifop, fluazinam, methamidophos, and thiamethoxam from surface water samples and determination by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. It was used the 2³ full factorial and the Doehlert experimental designs. The extraction technique was optimized by evaluating the effects of the three variables: sample pH, ionic strength (addition of Na₂HPO₄), and organic solvent volume. Considering the interest to find an optimal condition for all analytes simultaneously, the best extraction parameters found were as follows: pH = 5.33, concentration of Na₂HPO₄ = 0.0088 mol L^-1 and organic phase volume = 4.5 mL. The optimized methodology showed LOD and LOQ levels from 0.33 to 8.13 ng L^-1 and from 1.09 to 26.84 ng L^-1, respectively. The recovery values ranged from 38.37 and 99.83% and the RSD values varied from 2.33 to 18.92%. The method was applied to surface water analysis sampled in areas with intensive agricultural practices in Ouro Branco City, Minas Gerais, Brazil. The difenoconazole was detected in concentrations between 12.53 and 94.76 ng L^-1.