Multi-residue analytical methods using LC-tandem MS for the determination of pharmaceuticals in environmental and wastewater samples: a review

A LC-MS/MS method for the simultaneous quantification of 17 opioids in biosolids

The solid product of wastewater treatment plants is commonly used as a fertiliser to increase sustainability and waste reuse. It has undergone extensive treatment to remove high nutrient loads, pathogens and heavy metals but the extensive matrix of household chemicals, pesticides and pharmaceuticals remains, untargeted by most treatment technologies. These compounds, particularly pharmaceuticals, have been detected in biosolids with there being evidence of uptake by plants. With the current opioid pandemic in North America and overprescription, a simple method is required for the extraction of opioids from a solid medium as to ascertain the concentrations the environment is exposed to. A sonication-liquid-liquid extracted method was developed where biosolids were suspended in water and extracted using ethyl acetate before analysis on LC MS/MS. Sodium and potassium chloride were compared along with acidic and alkaline conditions. The optimised method utilised NaCl at a pH of 12 and was validated for 17 opioids, achieving linearity >0.987, 86-113% matrix effect and 0.1-10 μg/kg limits of detection. Upon analysis of biosolids destined for agriculture, 14 opioids were detected across all samples in a concentration range of 1-289 μg/kg.

Prevalence of carbapenem resistance in Acinetobacter baumannii and Pseudomonas aeruginosa in sub-Saharan Africa: A systematic review and meta-analysis

Carbapenems are effective drugs against bacterial pathogens and resistance to them is considered a great public health threat, especially in notorious nosocomial pathogens like Acinetobacter baumannii and Pseudomonas aeruginosa. In this study, we aimed to determine the prevalence of carbapenem resistance in A. baumannii and P. aeruginosa infections in Sub-Saharan Africa. Databases (PubMed, Scopus, Web of Science, and African Journal Online) were systematically searched following the Preferred Reporting Items for Systematic review and meta-analysis protocols (PRISMA-P) 2020 statements for articles reporting carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) prevalence between 2012 and 2022. Pooled prevalence was determined with the random effect model and funnel plots were used to determine heterogeneity in R. A total of 47 articles were scanned for eligibility, among which 25 (14 for carbapenem-resistant A. baumannii and 11 for carbapenem-resistant P. aeruginosa) were included in the study after fulfilling the eligibility criteria. The pooled prevalence of CRPA in the present study was estimated at 8% (95% CI; 0.02-0.17; I2 = 98%; P <0.01). There was high heterogeneity (Q = 591.71, I2 = 98.9%; P<0.0001). In addition, this study's pooled prevalence of CRAB was estimated at 20% (95% CI; 0.04-0.43; I2 = 99%; P <0.01). There was high heterogeneity (Q = 1452.57, I2 = 99%; P<0.0001). Also, a funnel plot analysis of the studies showed high degree of heterogeneity. The carbapenemase genes commonly isolated from A. baumannii in this study include blaOXA23, blaOXA48, blaGES., blaNDM, blaVIM, blaOXA24, blaOXA58, blaOXA51, blaSIM-1, blaOXA40, blaOXA66, blaOXA69, blaOXA91, with blaOXA23 and blaVIM being the most common. On the other hand, blaNDM, blaVIM, blaIMP, blaOXA48, blaOXA51, blaSIM-1, blaOXA181, blaKPC, blaOXA23, blaOXA50 were the commonly isolated carbapenemase genes in P. aeruginosa, among which blaVIM and blaNDM genes were the most frequently isolated. Surveillance of drug-resistant pathogens in Sub-Saharan Africa is essential in reducing the region's disease burden. This study has shown that the region has significantly high multidrug-resistant pathogen prevalence. This is a wake-up call for policymakers to put in place measures to reduce the spread of these critical priority pathogens.

Influence of two anti-tumor drugs, pazopanib, and axitinib, on the development and thyroid-axis of zebrafish (Danio rerio) embryos/larvae

Introduction

In recent years, the potential toxicities of different pharmaceuticals toward the thyroid system have received increasing attention. In this study, we aim to evaluate the toxic effects of pazopanib and axitinib, two anti-tumor drugs with widespread clinical use, on thyroid function in the zebrafish model.

Methods

We measured levels of thyroid-related hormones using the commercial Enzyme-Linked Immunosorbent Assay (ELISA) kit. Whole-mount in situ hybridization (WISH) analysis was employed to detect target gene expression changes. Morphology of the thyroid were evaluated by using transgenic Tg (tg: EGFP) fish line under a confocal microscope. The relative mRNA expression of key genes was verified through quantitative real-time polymerase chain reaction (RT‒qPCR). The size and number of the follicles was quantified whereby Hematoxylin-Eosin (H & E) staining under a light microscope.

Results

The results revealed that fertilized zebrafish embryos were incubated in pazopanib or axitinib for 96 hours, development and survival were significantly affected, which was accompanied by significant disturbances in thyroid endocrine system (e.g., increased thyroid-stimulating hormone (TSH) content and decreased triiodothyronine (T3) and thyroxine (T4) content, as well as transcription changes of genes associated with the hypothalamus-pituitary-thyroid (HPT) axis. Moreover, based on whole-mount in situ hybridization staining of tg and histopathological examination of zebrafish embryos treated with pazopanib and axitinib, we observed a significantly abnormal development of thyroid follicles in the Tg (tg: EGFP) zebrafish transgenic line.

Conclusion

Collectively, these findings indicate that pazopanib and axitinib may have toxic effects on thyroid development and function, at least partially, by influencing the regulation of the HPT axis. Thus, we believe that the potential thyroid toxicities of pazopanib and axitinib in their clinical applications should receive greater attention.

Quantitative analysis of polycyclic aromatic hydrocarbons using high-performance liquid chromatography-photodiode array-high-resolution mass spectrometric detection platform coupled to electrospray and atmospheric pressure photoionization sources

Polycyclic aromatic hydrocarbons (PAHs) are common pollutants present in atmospheric aerosols and other environmental mixtures. They are of particular air quality and human health concerns as many of them are carcinogenic toxins. They also affect absorption of solar radiation by aerosols, therefore contributing to the radiative forcing of climate. For environmental chemistry studies, it is advantageous to quantify PAH components using the same analytical technics that are commonly applied to characterize a broad range of polar analytes present in the same environmental mixtures. Liquid chromatography coupled with photodiode array and high-resolution mass spectrometric detection (LC-PDA-HRMS) is a method of choice for comprehensive characterization of chemical composition and quantification of light absorption properties of individual organic compounds present in the environmental samples. However, quantification of non-polar PAHs by this method is poorly established because of their imperfect ionization in electrospray ionization (ESI) technique. This tutorial article provides a comprehensive evaluation of the quantitative analysis of 16 priority pollutant PAHs in a standard reference material using the LC-MS platform coupled with the ESI source. Results are further corroborated by the quantitation experiments using an atmospheric pressure photoionization (APPI) method, which is more sensitive for the PAH detection. The basic concepts and step-by-step practical guidance for the PAHs quantitative characterization are offered based on the systematic experiments, which include (1) Evaluation effects of different acidification levels by formic acid on the (+)ESI-MS detection of PAHs. (2) Comparison of detection limits in ESI+ versus APPI+ experiments. (3) Investigation of the PAH fragmentation patterns in MS2 experiments at different collision energies. (4) Calculation of wavelength dependent mass absorption coefficient (MACλ) of the standard mixture and its individual PAHs using LC-PDA data. (5) Assessment of the minimal injected mass required for accurate quantification of MACλ of the standard mixture and of a multi-component environmental sample.

Screening and Risk Evaluation of Organic Contaminants in an Urban Wetland Fed with Wastewater Effluents

Wastewater release in an urban wetland in Mexico City entails discharging complex mixtures of hundreds of chemical substances into the aquatic system. Therefore, in order to identify the most important contaminants, a GC-MS screening method coupled with deconvolution software was used. LC₅₀ values from ECOSAR and Toxic Units were obtained to identify the organic pollutants-of-concern and to pinpoint the most ecotoxic sites. The results showed that, even though the area has intensive farming, agrochemicals are not of concern. Industrial and domestic groups make up from about 30%-66% of the pollutants for all sites. Of the 189 identified substances, 17 were detected 44% of the time and the Toxic Unit showed that terbutol, coprostanol, and hexadecane were capable of generating considerable adverse effects on the aquatic ecosystem. Total Toxic Units for each site exhibited a decreasing trend as they distanced from the urban and agricultural area.

Performance and mechanism of sulfamethoxazole removal in different bioelectrochemical technology-integrated constructed wetlands

Sulfamethoxazole (SMX) has a high concentration and detection frequency in aquatic environments due to the poor removal efficiency of traditional biological treatment processes. Bioelectrochemical technology-integrated constructed wetlands (CWs) have great potential for SMX removal; however, the process of SMX removal in different bioelectrochemical technology-integrated CWs (microbial fuel cell (MFC) and direct current (EC)) remains unclear. To address this, we examined the mechanism of SMX removal in MFCCW and ECCW. The results revealed that the SMX removal efficiency can reach 96.0 ± 2.4% in the ECCW and 97.2 ± 2.2% in the MFCCW. The enhancement of MFC for SMX removal in CW was slightly better than that in direct current (p > 0.05). It was found that the adsorption process of SMX in the substrate promoted by EC was more enhanced than that by MFC. Furthermore, bioelectrochemical technology improved plant activity, including root and enzymatic (superoxide dismutase, peroxidase, and catalase) activities, and fluorescence parameters (photochemical quenching coefficient, non-photochemical quenching coefficient, and quantum efficiency of PS II). Significant differences were found between CW and ECCW (p < 0.05), while no significant differences were found between CW and MFCCW (p > 0.05). The microbial activity and abundance in CW were improved by bioelectrochemical technology, and the microbial community structure was optimised to be simpler and more stable. However, EC tended to promote microbial and plant activity in CW, whereas MFC tended to optimise the microbial community and improve the tightness and stability of the module. The enhanced difference might also account for the changes in the SMX degradation pathway. 4-aminobenzenesulfonic acid (TP174), 3-amino-5-methylisoxazole (TP99) and 5-methylisoxazole (TP84) were all common products in the three reactors, whereas TP99 underwent further ring-opening in MFCCW and TP174 underwent further hydrolysis in ECCW. This study provided an important reference for the targeted regulation of plants and microorganisms in constructed wetlands via different bioelectrochemistry to enhance characteristic pollutants degradation.

Effects of paracetamol on the polychaete Hediste diversicolor: occurrence of oxidative stress, cyclooxygenase inhibition and behavioural alterations

Pharmaceuticals are significant environmental stressors, since they are utilized around the world; they are usually released in to the aquatic system without adequate treatment and several non-target species can be harmed because of their intrinsic properties. Paracetamol is one of the most widely prescribed analgesics in human medical care. Consequently, this compound is systematically reported to occur in the wild, where it may exert toxic effects on non-target species, which are mostly uncharacterized so far. The objective of the present work was to assess the acute (control, 5, 25, 125, 625 and 3125 μg/L) and chronic (control, 5, 10, 20, 40 and 80 μg/L) effects of paracetamol on behavioural endpoints, as well as on selected oxidative stress biomarkers [superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRed)] and the anti-inflammatory activity biomarker cyclooxygenase (COX), in the polychaete Hediste diversicolor (Annelida: Polychaeta). Exposure to paracetamol caused effects on behavioural traits, with increased burrowing time (96 h) and hypoactivity (28 days). In addition, exposure to paracetamol resulted also in significant increases of SOD activity, but only for intermediate levels of exposure, but for both acute and chronic exposures. Both forms of GPx had their activities significantly increased, especially after chronic exposure. Acutely exposed organisms had their GRed significantly decreased, while chronically exposed worms had their GRed activity augmented only for the lowest tested concentrations. Effects were also observed in terms of COX activity, showing that paracetamol absorption occurred and caused an inhibition of COX activity in both exposure regimes. It is possible to conclude that the exposure to concentrations of paracetamol close to the ones in the environment may be deleterious to marine ecosystems, endangering marine life by changing their overall redox balance, and the biochemical control of inflammatory intermediaries. Behaviour was also modified and the burrowing capacity was adversely affected. This set of effects clearly demonstrate that paracetamol exposure, under realistic conditions, it not exempt of adverse effects on marine invertebrates, such as polychaetes.

Quality by design optimization of a liquid chromatographic-tandem mass spectrometric method for the simultaneous analysis of structurally heterogeneous pharmaceutical compounds and its application to the rapid screening in wastewater and surface water samples by large volume direct injection

This study focused on the Analytical Quality by Design (AQbD) optimization of the chromatographic separation and mass spectrometric detection of a wide group of structurally heterogeneous model pharmaceutical compounds (PhCs) and transformation products (TPs), chosen to cover the challenging issues of the co-presence of compounds characterized by (i) a wide range of physicochemical properties, (ii) the same mass transitions, and (iii) different ionisation modes. Italian consumption of PhCs were also considered as election criteria of target analytes. Octadecyl and pentafluorophenyl stationary phases, acetonitrile/methanol ratios and acidity of the eluents, column temperature, initial organic phase percentage, and elution gradient were investigated by AQbD, aiming at optimizing critical resolutions, sensitivities, and analysis time. Statistically significant models were obtained in most cases with fitting and cross-validation coefficients in the ranges of 0.681-0.998 and 0.514-0.967, respectively. After optimization, the analysis of target analytes was performed in a single chromatographic run, adopting a mixed acquisition mode based on scheduled acquisition windows comprising both single polarity and continuous polarity switching. For most investigated analytes the method provided detection limits in the sub-ng/L to low ng/L range, meeting for macrolides the sensitivity requested by the "Watch List" 2018/840/EU. The optimized method was applied to the direct injection analysis of PhCs and TPs in four wastewater treatment plant (WWTP) effluents and surface water (SW) samples collected in the receiving water bodies. Absolute values of matrix effect were found to be far higher than 20% for most target analytes in most samples. Seventeen PhCs and two TPs were quantified in at least one sample, at the wide concentration range of about 1-3200 ng/L. The most occurring PhCs in both WWTP effluents and SWs were levofloxacin (202-1239 and 100-830 ng/L), furosemide (865-3234 and 230-880 ng/L), ketoprofen (295-1104 and 270-490 ng/L), and ibuprofen (886-3232 and 690-1440 ng/L).

Overview of Sample Preparation and Chromatographic Methods to Analysis Pharmaceutical Active Compounds in Waters Matrices

In the environment, pharmaceutical residues are a field of particular interest due to the adverse effects to either human health or aquatic and soil environment. Because of the diversity of these compounds, at least 3000 substances were identified and categorized into 49 different therapeutic classes, and several actions are urgently required at multiple steps, the main ones: (i) occurrence studies of pharmaceutical active compounds (PhACs) in the water cycle; (ii) the analysis of the potential impact of their introduction into the aquatic environment; (iii) the removal/degradation of the pharmaceutical compounds; and, (iv) the development of more sensible and selective analytical methods to their monitorization. This review aims to present the current state-of-the-art sample preparation methods and chromatographic analysis applied to the study of PhACs in water matrices by pinpointing their advantages and drawbacks. Because it is almost impossible to be comprehensive in all PhACs, instruments, extraction techniques, and applications, this overview focuses on works that were published in the last ten years, mainly those applicable to water matrices.

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.

Toxicity of the Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) acetylsalicylic acid, paracetamol, diclofenac, ibuprofen and naproxen towards freshwater invertebrates: A review

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) represent one of the main therapeutic classes of molecules contaminating aquatic ecosystems worldwide. NSAIDs are commonly and extensively used for their analgesic, antipyretic and anti-inflammatory properties to cure pain and inflammation in human and veterinary therapy. After use, NSAIDs are excreted in their native form or as metabolites, entering the aquatic ecosystems. A number of monitoring surveys has detected the presence of different NSAIDs in freshwater ecosystems in the ng/L - μg/L concentration range. Although the concentrations of NSAIDs in surface waters are low, the high biological activity of these molecules may confer them a potential toxicity towards non-target aquatic organisms. The present review aims at summarizing toxicity, in terms of both acute and chronic toxicity, induced by the main NSAIDs detected in surface waters worldwide, namely acetylsalicylic acid (ASA), paracetamol (PCM), diclofenac (DCF), ibuprofen (IBU) and naproxen (NPX), both singularly and in mixture, towards freshwater invertebrates. Invertebrates play a crucial role in ecosystem functioning so that NSAIDs-induced effects may result in hazardous consequences to the whole freshwater trophic chain. Acute toxicity of NSAIDs occurs only at high, unrealistic concentrations, while sub-lethal effects arise also at low, environmentally relevant concentrations of all these drugs. Thus, further studies represent a priority in order to improve the knowledge on NSAID toxicity and mechanism(s) of action in freshwater organisms and to shed light on their real ecological hazard towards freshwater communities.

Spatial variation in the detection rates of frequently studied pharmaceuticals in Asian, European and North American rivers

Pharmaceutical consumption has expanded rapidly during the last century and their persistent presence in the environment has become a major concern. Unfortunately, our understanding of the distribution of pharmaceuticals in surface water and their effects on aquatic biota and public health is limited. Here, we explore patterns in the detection rate of the most frequently studied pharmaceuticals in 64 rivers from 22 countries using bi-clustering algorithms and subsequently analyze the results in the context of regional differences in pharmaceutical consumption habits, social and environmental factors, and removal-efficiency of wastewater treatment plants (WWTP). We find that 20% of the pharmaceuticals included in this analysis are pervasively present in all the surface waterbodies. Several pharmaceuticals also display low overall positive detection rates; however, they exhibit significant spatial variability and their detection rates are consistently lower in Western European and North America (WEOG) rivers in comparison to Asian rivers. Our analysis suggests the important role of pharmaceutical consumption and population in governing these patterns, however the role of WWTP efficiency appeared to be limited. We were constrained in our ability to assess the role of hydrology, which most likely also plays an important role in regulating pharmaceuticals in rivers. Most importantly though, we demonstrate the ability of our algorithm to provide probabilistic estimates of the detection rate of pharmaceuticals that were not studied in a river, an exercise that could be useful in prioritizing pharmaceuticals for future study.

Determination of 5-fluorocytosine, 5-fluorouracil, and 5-fluorouridine in hospital wastewater by liquid chromatography-mass spectrometry

Chemotherapeutics are pharmaceutical compounds the occurrence of which in the environment is of growing concern because of the increase in treatments against cancer diseases. They can reach the aquatic ecosystems after passing through wastewater treatment plants without complete removal. One of the most frequently used chemotherapeutics is 5-fluorouracil which exhibits a strong cytostatic effect. In this paper, an analytical methodology was developed, validated, and applied to determine 5-fluorouracil, its precursor, 5-fluorocytosine, and its major active metabolite, 5-fluorouridine, in hospital wastewater samples. Due to the expected low concentrations after dilution and interferences present in such a complex matrix, a very selective and sensitive detection method is required. Moreover, an extraction method must be implemented prior to the determination in order to purify the sample extract and preconcentrate the target analytes at micrograms per liter concentration levels. Solid-phase extraction followed by liquid chromatography with tandem mass spectrometry was the combination of choice and all included parameters were studied. Under optimized conditions for wastewater samples analysis, recoveries from 63 to 108% were obtained, while intraday and interday relative standard deviations never exceeded 20 and 25%, respectively. Limits of detection between 61 and 620 ng/L were achieved. Finally, the optimized method was applied to samples from hospital wastewater effluents.

Towards the Removal of Antibiotics Detected in Wastewaters in the POCTEFA Territory: Occurrence and TiO2 Photocatalytic Pilot-Scale Plant Performance

This research aims to assess the presence of four antibiotic compounds detected in the influent and effluent of wastewater treatment plants (WWTPs) in the POCTEFA territory (north of Spain and south of France) during the period of 2018–2019, and to relate the removal of antibiotic compounds with the processes used in the WWTPs. The performance of a photocatalytic TiO2/UV-VIS pilot-scale plant was then evaluated for the degradation of selected antibiotics previously detected in urban treated effluent. The main results reflect that azithromycin had the highest mass loadings (11.3 g/day per 1000 inhabitants) in the influent of one of the selected WWTPs. The results also show considerable differences in the extent of antibiotics removal in WWTPs ranging from 100% for sulfadiazine to practically 0% for trimethoprim. Finally, the photocatalytic TiO2/UV-VIS pilot-scale plant achieved the removal of the four antibiotics after 240 min of treatment from 78%–80% for trimethoprim and enrofloxacin, up to 100% for amoxicillin, sulfadiazine and azithromycin. The catalyst recovery via mechanical coagulation–flocculation–decantation was almost total. The Ti concentration in the effluent of the TiO2/UV-VIS pilot-scale plant was lower than 0.1% (w/w), and its release into the environment was subsequently minimized.

Enzyme response of activated sludge to a mixture of emerging contaminants in continuous exposure

The relevant information about the impacts caused by presence of emerging pollutants in mixtures on the ecological environment, especially on the more vulnerable compartments such as activated sludge (AS) is relatively limited. This study investigated the effect of ibuprofen (IBU) and triclosan (TCS), alone and in combination to the performance and enzymatic activity of AS bacterial community. The assays were carried out in a pilot AS reactor operating for two-weeks under continuous dosage of pollutants. The microbial activity was tracked by measuring oxygen uptake rate, esterase activity, oxidative stress and antioxidant enzyme activities. It was found that IBU and TCS had no acute toxic effects on reactor biomass concentration. TCS led to significant decrease of COD removal efficiency, which dropped from 90% to 35%. Continuous exposure to IBU, TCS and their mixtures increased the activities of glutathione s-transferase (GST) and esterase as a response to oxidative damage. A high increase in GST activity was associated with non-reversible toxic damage while peaks of esterase activity combined with moderate GST increase were attributed to an adaptive response.

Prevalence and molecular analysis of multidrug-resistant Acinetobacter baumannii in the extra-hospital environment in Mthatha, South Africa

Introduction

The presence of Acinetobacter baumannii outside hospitals remains unclear. This study aimed to determine the prevalence of multidrug-resistance (MDR) A. baumannii in the extra-hospital environment in Mthatha, South Africa and to investigate the frequency of carbapenemase-encoding genes.

Material and Methods

From August 2016 to July 2017 a total of 598 abattoir samples and 689 aquatic samples were collected and analyzed presumptively by cultural methods for the presence of A. baumannii using CHROMagar™ Acinetobacter medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL) and confirmed by the detection of their intrinsic bla_OXA-51 gene. Confirmed MDR A. baumannii isolates were screened for the presence of carbapenemase-encoding genes, ISAba1 insertion sequence and integrase intI1.

Results

In total, 248 (19.3%) Acinetobacter species were isolated. Acinetobacter. baumannii was detected in 183 (73.8%) of which 85 (46.4%) and 98 (53.6%) were recovered from abattoir and aquatic respectively. MDR A. baumannii was detected in 56.5% (48/85) abattoir isolates and 53.1% (52/98) aquatic isolates. Isolates showed high resistance to antimicrobials most frequently used to treat Acinetobacter infections such as piperacillin/tazobactam; abattoir (98% of isolates resistant), aquatic (94% of isolates resistant), ceftazidime (84%, 83%), ciprofloxacin (71%, 70%), amikacin (41%, 42%), imipenem (75%, 73%), and meropenem (74%, 71%). All the isolates were susceptible to tigecycline and colistin. All the isolates carried bla_OXA-51-like. The bla_OXA-23 was detected in 32 (66.7%) abattoir isolates and 11 (21.2%) aquatic isolates. The bla_OXA-58-like was positive in 7 (14.6%) and 4 (7.7%) abattoir and aquatic isolates, respectively. Both groups of isolates lacked bla_OXA-24-like, bla_IMP-type, bla_VIM-type, bla_NDM-1,bla_SIM, bla_AmpC, ISAba1 and inI1. Isolates showed high level of Multiple Antibiotic Resistance Index (MARI) ranging from 0.20-0.52.

Conclusion

Extra-hospital sources such as abattoir and aquatic environments may be a vehicle of spread of MDR A. baumannii strains in the community and hospital settings.

Occurrence, removal and seasonal variation of pharmaceuticals in Brasilian drinking water treatment plants

The presence of pharmaceuticals in aquatic environments has become a major issue of concern for scientific community, since there is a lack of information about risks and impacts to the environment and public health. In the context of Brazil, many cities do not have Wastewater Treatment Plants (WWTPs) and domestic sewage is dumped directly into the water bodies, aggravating the problem. Thus, the present study aimed to evaluate the presence of 28 prescribed pharmaceuticals from different therapeutic classes in six full-scale Drinking Water Treatment Plants (DWTPs) in Minas Gerais state. Samples were collected in twelve field campaigns from August 2016 to August 2017 and water quality were monitored. Analytical methodology was based on solid phase extraction (C18 cartridge) followed by High Performance Liquid Chromatography (Prominence DGU/20A3 - Shimadzu) coupled to Mass Spectrometry (micrOTOF-QII - Bruker). Considering the 28 pharmaceuticals analyzed, 18 were detected in the surface water source at concentrations ranging from Method Quantification Limit (MQL) to 11,960 ng/L. In drinking water, the concentration of the 11 pharmaceuticals detected ranged from <MQL to 6323 ng/L. Betamethasone, Fluconazole, Atorvastatin and Prednisone were the most detected pharmaceuticals. The drinking water monitoring showed a decrease in the concentration of all detected pharmaceuticals, indicating some removal of these compounds by the water treatment processes. The removal efficiency assessed shows a great variation among different compounds, DWTPs and over the year, ranging from an average of 32% ± 6% (Prednisone -DWTP3) to 100% ± 0% for some pharmaceuticals. The highest total concentrations and the maximum concentration values for the most frequently detected pharmaceuticals were related to the winter due, presumably, to lower dilution and temperature. Trace levels of pharmaceuticals were detected in surface and drinking water in Brazil and conventional DWTPs were not able to remove the pharmaceuticals completely.

Disk solid-phase extraction of multi-class pharmaceutical residues in tap water and hospital wastewater, prior to ultra-performance liquid chromatographic-tandem mass spectrometry (UPLC-MS/MS) analyses

In this work, a new clean-up and pre-concentration method based on disk solid-phase extraction (SPE) was developed to determine multi-class pharmaceutical residues covering a wide range of polarities (log K ow values from -0.5 to 5.1) in water systems, prior to ultra-performance liquid chromatographic-tandem mass spectrometry (UPLC-MS/MS) analyses. Electrospray ionisation in positive and negative modes was used for the simultaneous determination of both acidic and basic pharmaceuticals. The performances of disk SPE and cartridge SPE were compared. The targeted pharmaceutical compounds list included bronchodilators, antidiabetic drugs, antihypertensive drugs, a lipid-lowering agent, analgesics, and anti-inflammatory drugs. Based on our results, the disk SPE demonstrated a higher sensitivity and recovery value and less analysis time as compared to the cartridge SPE method. The limits of detection (LOD) for the new method ranged from 0.02-3.2 ng L-1, 0.02-3.1 ng L-1 and 0.02-4.7 ng L-1 for tap, effluent and influent wastewater, respectively. The method's absolute recovery values ranged from 70% to 122% for tap water, 62% to 121% for effluent wastewater and 62% to 121% for influent wastewater, except for metformin in which the absolute recovery value was approximately 48% for all samples. Intra-day precision for tap water, effluent and influent wastewater ranged from 3-12%, 4-9% and 2-8%, respectively. The method developed was applied for the determination of targeted pharmaceuticals in tap, effluent, and influent wastewater from one hospital treatment plant in Malaysia. The results revealed that the highest concentrations of certain pharmaceuticals were up to 49 424 ng L-1 (acetaminophen) and 1763 ng L-1 (caffeine) in the influent and effluent wastewater, respectively. The results also showed a variation in the treatment efficiencies for the hospital treatment plant from one compound to another. Nevertheless, the removal efficiencies ranged from 0-99%.

Pharmaceutical Mixtures: Still A Concern for Human and Environmental Health

In the present work, recent data on the sources, occurrence and fate of human-use pharmaceutical active compounds (PhACs) in the aquatic environment have been reviewed. Since PhACs and their metabolites are usually present as mixtures in the environment at very low concentrations, a particular emphasis was placed onto the PhACs mixtures, as well as on their short-term and long-term effects against human and environmental health. Moreover, a general overview of the main conventional as well as of the latest trends in wastewaters decontaminant technologies was outlined. Advantages and disadvantages of current processes were also pointed out. It appears that numerous gaps still exist in the current knowledge related to this field of interest, and further studies should be conducted at the global level in order to ensure a more efficient monitorisation of the presence of PhACs and their metabolites into the aquatic environment and to develop new mitigation measures.

Antibiotics in the aquatic environments: A review of lakes, China

The potential threat of antibiotics to the environment and human health has raised significant concerns in recent years. The consumption and production of antibiotics in China are the highest in the world due to its rapid economic development and huge population, possibly resulting in the high detection frequencies and concentrations of antibiotics in aquatic environments of China. As a water resource, lakes in China play an important role in sustainable economic and social development. Understanding the current state of antibiotics in lakes in China is important. Closed and semi-closed lakes provide an ideal medium for the accumulation of antibiotics and antibiotic resistance genes (ARGs). This review summarizes the current levels of antibiotic exposure in relevant environmental compartments in lakes. The ecological and health risks of antibiotics are also evaluated. This review concludes that 39 antibiotics have been detected in the aquatic environments of lakes in China. The levels of antibiotic contamination in lakes in China is relatively high on the global scale. Antibiotic contamination is higher in sediment than water and aquatic organisms. Quinolone antibiotics (QNs) pose the greatest risks. The contents of antibiotics in aquatic organisms are far lower than their maximum residual limits (MRLs), with the exception of the organisms in Honghu Lake. The lakes experience high levels of ARG contamination. A greater assessment of ARG presence and antibiotic exposure are urgent.

Efficient removal of anti-inflammatory phenylbutazone from an aqueous solution employing a composite material based on poly(aniline-co-pyrrole)/multi-walled carbon nanotubes

Poly(Ani-co-Py)/MWCNT was synthesized by chemical oxidation in a triple-phase interface system and presented a high capacity for the removal of PBZ from wastewater.

Effects of exposure to pharmaceuticals (diclofenac and carbamazepine) spiked sediments in the midge, Chironomus riparius (Diptera, Chironomidae)

Human and veterinary pharmaceuticals and degradation products are continuously introduced into the environment. To date, there is a lack of information about the effects of pharmaceuticals in spiked toxicity tests with non-target organisms. In this study, we have evaluated the effects of exposure to two common pharmaceuticals in the midge Chironomus riparius in spiked sediment experiments. The selected pharmaceuticals are the nonsteroidal anti-inflammatory drug (NSAID): diclofenac (DF) and the anti-depressant drug carbamazepine (CBZ). In order to assess the effects of the pharmaceuticals, a chronic toxicity test with the midge was carried out. The endpoints survival, growth and developmental stage by means of biomass, were measured after 10days, and emergence rates and sex-ratio (male/female) were measured after 21days of exposure. Significant mortality was observed in organisms at day 10 with a 40% of larvae surviving in the highest exposure concentration of CBZ. DF decreased the emergence ratio with respect to the controls in organisms exposed at concentrations of 34.0μg·g^-1 whereas CBZ reduced the growth of the midges (30,6% with respect to the control) and induced a significant change in sex-ratio at concentrations of 31.4μg·g^-1. The results obtained in the present study indicate possible adverse effects on aquatic invertebrates, which should be taken into account for environmental risk assessment of pharmaceutical compounds in sediments.

Occurrence of pharmaceutical, recreational and psychotropic drug residues in surface water on the northern Antarctic Peninsula region

Human presence in the Antarctic is increasing due to research activities and the rise in tourism. These activities contribute a number of potentially hazardous substances. The aim of this study is to conduct the first characterisation of the pharmaceuticals and recreational drugs present in the northern Antarctic Peninsula region, and to assess the potential environmental risk they pose to the environment. The study consisted of a single sampling of ten water samples from different sources, including streams, ponds, glacier drains, and a wastewater discharge into the sea. Twenty-five selected pharmaceuticals and 21 recreational drugs were analysed. The highest concentrations were found for the analgesics acetaminophen (48.74 μg L^-1), diclofenac (15.09 μg L^-1) and ibuprofen (10.05 μg L^-1), and for the stimulant caffeine (71.33 μg L^-1). All these substances were detected in waters that were discharged directly into the ocean without any prior purification processes. The hazard quotient (HQ) values for ibuprofen, diclofenac and acetaminophen were far in excess of 10 at several sampling points. The concentrations of each substance measured and used as measured environmental concentration values for the HQ calculations are based on a one-time sampling. The Toxic Unit values indicate that analgesics and anti-inflammatories are the therapeutic group responsible for the highest toxic burden. This study is the first to analyse a wide range of substances and to determine the presence of pharmaceuticals and psychotropic drugs in the Antarctic Peninsula region. We believe it can serve as a starting point to focus attention on the need for continued environmental monitoring of these substances in the water cycle, especially in protected regions such as the Antarctic. This will determine whether pharmaceuticals and recreational drugs are hazardous to the environment and, if so, can be used as the basis for risk-assessment studies to prioritise the exposure to risk.

Identification of antibiotics in wastewater: current state of extraction protocol and future perspectives

The release and occurrence of antibiotics in the aquatic environment has generated increased attention in the past few decades. The residual antibiotic in wastewater is important in the selection for antimicrobial resistance among microorganisms and the possibility of forming toxic derivatives. This review presents an assessment of the advancement in methods for extraction of antibiotics with solid phase extraction and liquid-liquid extraction methods applied in different aquatic environmental media. These advanced methods do enhance specificity, and also exhibit high accuracy and recovery. The aim of this review is to assess the pros and cons of the methods of extraction towards identification of quinolones and sulphonamides as examples of relevant antibiotics in wastewater. The challenges associated with the improvements are also examined with a view of providing potential perspectives for better extraction and identification protocols in the near future. From the context of this review, magnetic molecular imprinted polymer is superior over the remaining extraction methods (with the availability of commercial templates and monomers), is based on less cumbersome extraction procedures, uses less solvent and has the advantage of its reusable magnetic phase.

Multi-class determination of pharmaceuticals in wastewaters by solid-phase extraction and liquid chromatography tandem mass spectrometry with matrix effect study

In this work, a multi-class analytical method for determination of 22 frequently used pharmaceuticals was developed and validated. Analytes were from different classes for example macrolides, fluoroquinolones, tetracyclines, sulfonamides, anthelmintics, anesthetics, and others. Method was intended for analysis of aqueous samples so the sample preparation was done using solid-phase extraction (SPE). Different sorbents (C8, C18, polymeric, and ion exchange sorbents) combining different eluents (methanol, ethanol, acetonitrile, acetone, ethyl acetate) were investigated during development of sample preparation step. Samples were analyzed using HPLC-MS/MS, and therefore, chromatographic and mass spectrometer conditions were investigated. Optimal extraction efficiencies for most of the investigated analytes were obtained with Oasis HLB polymeric sorbents with acetonitrile as eluent. A study of matrix effect was carried out for wastewater treatment plant (WWTP) influent and effluent. The method was validated for linearity, detection limits and quantification limits, repeatability, and reproducibility. Method detection limits were in the range of 2.0-204.0 ng L^-1 for WWTP influent except for sulfaguanidine and dexamethasone. Also, method detection limits for WWTP effluent were from 1.0 to 115.4 ng L^-1. Method was successfully applied for analysis of real wastewater samples from municipal wastewater treatment plant. In the influent, pharmaceuticals from all investigated groups were present and the concentrations were from 50.0 to 4914.3 ng L^-1 for influent and 26.9 to 1699.2 ng L^-1 for effluent. It was also reported that some pharmaceuticals showed higher concentrations in the wastewater effluent than in the influent.

Gold Nanostar Enhanced Surface Plasmon Resonance Detection of an Antibiotic at Attomolar Concentrations via an Aptamer-Antibody Sandwich Assay

A new sandwich assay for tetracycline (TC) involving a DNA aptamer and antibody pair is demonstrated in conjunction with gold nanostar (GNS) enhanced surface plasmon resonance (SPR) to achieve detection in the low attomolar range. GNS particles were covalently functionalized with the antibody probe (antiTC) and integrated into a surface sandwich assay in conjunction with a SPR gold chip modified with the TC-specific aptamer. After it was demonstrated that both affinity probes can bind simultaneously to TC, optimization of the assay was performed using either antiTC only or GNS-antiTC conjugates to interact with aptamer/TC complexes present on the chip surface. Target concentrations as low as 10 aM could be detected using GNS-antiTC's, which was >10³ times greater in performance than when using antiTC only. In addition, good selectivity was achieved with respect to other tetracycline derivative antibiotics, such as oxytetracycline (OTC) and chlortetracycline (CTC), both which are structurally similar to TC. As a demonstration of trace antibiotic analysis in environmental samples, the GNS enhanced sandwich assay was applied to analyze TC added to aliquots of local river water and the results validated by comparing to conventional high-performance liquid chromatography (HPLC) analysis.

Removal and attenuation of sewage effluent combined tracer signals of phosphorus, caffeine and saccharin in soil

Contaminants in septic tank effluent (STE) are expected to be removed by the soil system before discharging to the environment. However, potential contaminants such as phosphorus (P), caffeine and artificial sweeteners do find their way to watercourses impacting aquatic eco systems. In this study, the attenuation of STE P, caffeine and saccharin were investigated in untreated soil and in soil with reduced microbial activity, in aqueous solutions and in the complex matrix of STE. Time series sorption and desorption experiments using batch equilibrium and a column experiment of STE P attenuation were conducted. The results revealed that the soil distribution coefficients (K_d) were: P 81.57 > caffeine 22.16 > saccharin 5.98 cm³/g, suggesting greater soil affinity to P adsorption. The data revealed that 80% of saccharin and 33% of caffeine attenuation was associated with microbial activities rather than adsorption processes. However, a complete removal of saccharin and caffeine did not occur during the equilibration period, suggesting their leaching potential. The dominant mechanism of P attenuation was adsorption (chemical and physical), yielding P retention of >73% and 35% for P in aqueous solution and in STE matrix, respectively, for batch equilibrium. The soil in the column acted as effluent P sink retaining 125 μg P/g soil of effluent P. The attenuation of P, caffeine and saccharin in the aqueous solution was greater than in STE, suggesting that the complex composition of STE reduced soil adsorption ability, and that other substances present in STE may be competing for soil binding sites. The data revealed that caffeine and P had similarities in the interaction with soils and thus caffeine may be considered as a STE tracer of anthropogenic source of P in receiving waters.

Development of potential candidate reference materials for drugs in bottom sediment, cod and herring tissues

Regular use of a reference material and participation in a proficiency testing program can improve the reliability of analytical data. This paper presents the preparation of candidate reference materials for the drugs metoprolol, propranolol, carbamazepine, naproxen, and acenocoumarol in freshwater bottom sediment and cod and herring tissues. These reference materials are not available commercially. Drugs (between 7 ng/g and 32 ng/g) were added to the samples, and the spiked samples were freeze-dried, pulverized, sieved, homogenized, bottled, and sterilized by γ-irradiation to prepare the candidate materials. Procedures for extraction and liquid chromatography coupled with tandem mass spectrometry were developed to determine the drugs of interest in the studied material. Each target drug was quantified using two analytical procedures, and the results obtained from these two procedures were in good agreement with each other. Stability and homogeneity assessments were performed, and the relative uncertainties due to instability (for an expiration date of 12 months) and inhomogeneity were 10-25% and 4.0-6.8%, respectively. These procedures will be useful in the future production of reference materials.

An optimized SPE-LC-MS/MS method for antibiotics residue analysis in ground, surface and treated water samples by response surface methodology- central composite design

BACKGROUND

Antibiotic residues are being constantly identified in environmental waters at low concentration. Growing concern has been expressed over the adverse environmental and human health effects even at low concentration. Hence, it is crucial to develop a multi-residues analytical method for antibiotics to generate a considerable dataset which are necessary in the assessment of aquatic toxicity of environmental waters for aquatic organisms and human health. This work aimed to develop a reliable and sensitive multi-residue method based on high performance liquid chromatography coupled with quadrupole-linear ion trap tandem mass spectrometry (HPLC-MS-MS). The method was optimized and validated for simultaneous determination of four classes of antibiotics including, β-lactam, macrolide, fluoroquinolone and nitro-imidazole in treated, ground and surface water matrices.

METHODS

In order to optimize the solid phase extraction process, main parameters influencing the extraction process including, pH, the volume of elution solvent and the amount of Na₄EDTA were evaluated. The optimization of extraction process was carried out by response surface methodology using central composite design. Analysis of variance was performed for nine target antibiotics using response surface methodology.

RESULTS

The extraction recoveries were found to be sensitive to the independent variables of pH, the volume of elution solvent and the amount of Na₄EDTA. The extraction process was pH-dependent and pH was a significant model term in the extraction process of all target antibiotics. Method validation was performed in optimum operation conditions in which the recoveries were obtained in the range of 50-117% for seven antibiotics in spiked treated and ground water samples and for six antibiotics in spiked river water samples. Method validation parameters in terms of method detection limit were obtained in the range of 1-10 ng/L in treated water, 0.8-10 ng/L in the ground water and 0.8-25 ng/L in river water, linearity varied from 0.95 to 0.99 and repeatability in term of relative standard deviation values was achieved less than 10% with the exception for metronidazole and ceftriaxone. The developed method was applied to the analysis of target antibiotics in treated, ground and surface water samples.

CONCLUSIONS

Target antibiotics were analyzed in different water matrices including treated, ground and river water. Seven out of nine antibiotics were detected in Kan River and Firozabad Ditch water samples, although none of them were detected in treated water and ground water samples.

Antibiotic Resistant Superbugs: Assessment of the Interrelationship of Occurrence in Clinical Settings and Environmental Niches

The increasing threat to global health posed by antibiotic resistance remains of serious concern. Human health remains at higher risk due to several reported therapeutic failures to many life threatening drug resistant microbial infections. The resultant effects have been prolonged hospital stay, higher cost of alternative therapy, increased mortality, etc. This opinionated review considers the two main concerns in integrated human health risk assessment (i.e., residual antibiotics and antibiotic resistant genes) in various compartments of human environment, as well as clinical dynamics associated with the development and transfer of antibiotic resistance (AR). Contributions of quorum sensing, biofilms, enzyme production, and small colony variants in bacteria, among other factors in soil, water, animal farm and clinical settings were also considered. Every potential factor in environmental and clinical settings that brings about AR needs to be identified for the summative effects in overall resistance. There is a need to embrace coordinated multi-locational approaches and interrelationships to track the emergence of resistance in different niches in soil and water versus the hospital environment. The further integration with advocacy, legislation, enforcement, technological innovations and further research input and recourse to WHO guidelines on antibiotic policy would be advantageous towards addressing the emergence of antibiotic resistant superbugs.

Automated thin-film microextraction coupled to a flow-through cell: somewhere in between passive and active sampling

A prototype for the automated thin-film microextraction of pharmaceuticals from aqueous solutions has been developed and is presented here for the first time. With a software-controlled setup, extraction methods for ivermectin and iohexol have been developed. The widely used antiparasitic agent ivermectin is non-polar and has a high tendency to sorb to surfaces. In contrast to this, the nonionic but polar iodinated X-ray contrast agent iohexol is freely water soluble. With these two substances, a wide range of polarity is covered. Sorption kinetics and thermodynamics of ivermectin and iohexol were studied. With the presented passive sampling approach, it was possible to extract up to 96.2% ivermectin with a C₁₈-phase within 1 h and up to 74.6% of iohexol with a PS-DVB phase within 36 h out of water. Using abamectin as internal standard, it was possible to quantitatively follow dissipation of ivermectin in a simulated surface water experiment. Predominantly, the newly developed prototype can be used for automated and time-resolved extraction of xenobiotics from waterbodies under field conditions, for the extraction of substances under laboratory conditions as an alternative to the elaborate solid-phase extraction, and for the automated control of chemical reaction kinetics.

Occurrence and removal of multiple classes of antibiotics and antimicrobial agents in biological wastewater treatment processes

Very little information on the occurrence and fate of multiple classes of antimicrobials in the aquatic environment is reported for the Southeast Asian region. This study provides the first and comprehensive data on the occurrence of ten different classes of antimicrobials in wastewater samples for Singapore. Among the investigated antimicrobials, 19 out of 21 target compounds were detected in 100% of the collected raw influent samples. Concentrations of the detected antimicrobials in raw influent varied from 23.8 to 43,740 ng/L. Removal of antimicrobials by conventional activated sludge (CAS) and membrane bioreactor (MBR) systems at a local wastewater treatment plant was evaluated. MBR exhibited better performance over CAS for most target antimicrobials. Beta-lactam, glycopeptide, and fluoroquinolone classes were largely eliminated by biological wastewater treatment processes, whereas trimethoprim and lincosamides appeared to be persistent. Effects of physicochemical properties and chemical structures of target antimicrobials on their removal efficiencies/mechanisms during wastewater treatment process were also discussed.

Status of hormones and painkillers in wastewater effluents across several European states-considerations for the EU watch list concerning estradiols and diclofenac

Present technologies for wastewater treatment do not sufficiently address the increasing pollution situation of receiving water bodies, especially with the growing use of personal care products and pharmaceuticals (PPCP) in the private household and health sector. The relevance of addressing this problem of organic pollutants was taken into account by the Directive 2013/39/EU that introduced (i) the quality evaluation of aquatic compartments, (ii) the polluter pays principle, (iii) the need for innovative and affordable wastewater treatment technologies, and (iv) the identification of pollution causes including a list of principal compounds to be monitored. In addition, a watch list of 10 other substances was recently defined by Decision 2015/495 on March 20, 2015. This list contains, among several recalcitrant chemicals, the painkiller diclofenac and the hormones 17β-estradiol and 17α-ethinylestradiol. Although some modern approaches for their removal exist, such as advanced oxidation processes (AOPs), retrofitting most wastewater treatment plants with AOPs will not be acceptable as consistent investment at reasonable operational cost. Additionally, by-product and transformation product formation has to be considered. The same is true for membrane-based technologies (nanofiltration, reversed osmosis) despite of the incredible progress that has been made during recent years, because these systems lead to higher operation costs (mainly due to higher energy consumption) so that the majority of communities will not easily accept them. Advanced technologies in wastewater treatment like membrane bioreactors (MBR) that integrate biological degradation of organic matter with membrane filtration have proven a more complete elimination of emerging pollutants in a rather cost- and labor-intensive technology. Still, most of the presently applied methods are incapable of removing critical compounds completely. In this opinion paper, the state of the art of European WWTPs is reflected, and capacities of single methods are described. Furthermore, the need for analytical standards, risk assessment, and economic planning is stressed. The survey results in the conclusion that combinations of different conventional and advanced technologies including biological and plant-based strategies seem to be most promising to solve the burning problem of polluting our environment with hazardous emerging xenobiotics.

Simultaneous determination of aditoprim and its three major metabolites in pigs, broilers and carp tissues, and its application in tissue distribution and depletion studies

Aditoprim (ADP) is a recently developed dihydrofolate reductase inhibitor that has shown promise for therapeutic use in veterinary medicine because of its excellent pharmacokinetic properties. In this study, a sensitive and reliable multi-residue chromatography-ultraviolet (HPLC-UV) method for the quantitative analysis of ADP and its three major metabolites was developed, and the tissue distribution and depletion profiles of ADP and its major metabolites in pigs, broilers and carp were investigated. Edible and additional tissues (heart, lung, stomach, intestine and swim bladder) were collected for analysis at six different withdrawal periods after ADP administration for 7 days. ADP, N-monomethyl-ADP and N-didesmethyl-ADP were detected in almost all tissues in the three species. The liver, kidney and lung showed higher residue concentrations, and the liver showed a longer residue half-life (t1/2) than other tissues. In the liver, ADP was the most abundant component with the longest persistence. The results suggest that the liver was the residual target tissue and ADP was the marker residue, and the conclusive withdrawal time (WDT) of 20 days in pigs, 16 days in broilers and 25 days in carp was estimated using the assessment methodologies approved by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Levels of pharmaceuticals in Slovene municipal and hospital wastewaters: a preliminary study

Pharmaceuticals in wastewater have clearly raised concern and a broad range of analytical methods has been used to assess the risk as accurately as possible. The aim of our study was to measure and compare the concentrations of atorvastatin, bisoprolol, carbamazepine, ciprofloxacin, clofibric acid, diclofenac, fluoxetine, metoprolol, and sertraline in wastewater samples taken from one municipal and one hospital wastewater treatment plant in Slovenia and to predict the potential environmental burden using the risk quotient. In both effluents only clofibric acid and fluoxetine were not detected. The measured concentrations of the remaining seven pharmaceuticals varied between the ng L−1 and the μg L−1 range. Hospital effluent showed higher concentrations, except for diclofenac and carbamazepine. However, high risk quotient was found only for ciprofloxacin and diclofenac in both municipal and hospital effluent. In conclusion, our method can provide a useful tool for systematic monitoring of pharmaceuticals commonly found in wastewater, which will enable a reliable assessment of the risks for the aquatic biota and humans. Knowing the risks will help to plan wastewater treatment and preserve our environment.

Pharmaceutical concentrations in screened municipal wastewaters in Victoria, British Columbia: A comparison with prescription rates and predicted concentrations

Pharmaceuticals and personal care products (PPCPs) are emerging chemicals of concern detected in surface waters globally. Recent reviews advocate that PPCP occurrence, fate, and exposure need to be better predicted and characterized. The use of pharmaceutical prescription rates to estimate PPCP concentrations in the environment has been suggested. Concentrations of 7 pharmaceuticals (acetylsalicylic acid, diclofenac, fenoprofen, gemfibrozil, ibuprofen, ketoprofen, and naproxen) were measured in municipal wastewater using gas chromatography/ion trap-tandem mass spectroscopy (GC/IT-MS/MS). Subregional pharmaceutical prescription data were investigated to determine whether they could predict measured effluent concentrations (MECs) in wastewaters. Predicted effluent concentrations (PECs) for 5 of the 7 pharmaceuticals were within 2-fold agreement of the MECs when the fraction of parent pharmaceutical excreted was not considered. When the fraction of parent pharmaceutical excreted was considered, the respective PECs decreased, and most were within an order of magnitude of the MECs. Regression relationships of monthly PECs versus MECs were statistically significant (p < 0.05) but weak (R(2) = 0.18-0.56) for all pharmaceuticals except ketoprofen. This suggests high variability in the data and may be the result of factors influencing MECs such as the analytical methods used, wastewater sampling frequency, and methodology. The PECs were based solely on prescription rates and did not account for inputs of pharmaceuticals that had a significant over-the-counter component or were from other sources (e.g., hospitals).