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Storm events lead to agricultural and urban runoff, to mobilization of contaminated particulate matter, and to input from combined sewer overflows into rivers. We conducted time‐resolved sampling during a storm event at the Ammer River, southwest Germany, which is representative of small river systems in densely populated areas with a temperate climate. Suspended particulate matter (SPM) and water from 2 sampling sites were separately analyzed by a multi‐analyte liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for 97 environmentally relevant organic micropollutants and with 2 in vitro bioassays. Oxidative stress response (AREc32) may become activated by various stressors covering a broad range of physicochemical properties and induction of aryl hydrocarbon receptor–chemical‐activated luciferase gene expression (AhR‐CALUX) by hydrophobic compounds such as dioxins and dioxin‐like molecules. Compound numbers, concentrations, their mass fluxes, and associated effect fluxes increased substantially during the storm event. Micropollutants detected in water and on SPM pointed toward inputs from combined sewer overflow (e.g., caffeine, paracetamol), urban runoff (e.g., mecoprop, terbutryn), and agricultural areas (e.g., azoxystrobin, bentazone). Particle‐facilitated transport of triphenylphosphate and tris(1‐chloro‐2‐propyl) phosphate accounted for up to 34 and 33% of the total mass flux even though SPM concentrations were <1 g L–1. Effect fluxes attributed to SPM were similar or higher than in the water phase. The important role of SPM‐bound transport emphasizes the need to consider not only concentrations but also mass and effect fluxes for surface water quality assessment and wastewater/stormwater treatment options. Environ Toxicol Chem 2021;40:88–99. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The application of contaminated paper sludge on arable land in southwest Germany caused the occurrence of a broad range of poly- and perfluoroalkyl substances (PFASs) on soil. Recently, the dead-end transformation products (TPs) perfluorooctanoic acid and perfluorooctanesulfonic acid were detected in groundwater and drinking water. The precursors and other transformation products mostly remained unknown. Therefore, HRMS screening by Kendrick mass analysis and assignment of homologous series in combination with suspect screening were applied to identify original PFASs and their TPs in four different soil samples from sites where contaminated paper sludge was applied. In total, twelve compound classes comprising more than 61 PFASs could be fully or tentatively identified. The data reveal that contamination mainly originates from polyfluorinated dialkylated phosphate esters (from 4:2/6:2 to 12:2/14:2), N-ethyl perfluorooctane sulfonamide ethanol–based phosphate diesters (only C8/C8) and transformation products of these precursors. Contamination patterns can be attributed to PFASs used for paper impregnation and can vary slightly from site to site. [ABSTRACT FROM AUTHOR]

Abstract The aim of the study was to investigate the biodegradability of guanyl urea (GU) and the behavior of other transformation products (TPs) of Metformin (MF). Most biodegradation studies of MF with activated sludge of waste water treatment plants (WWTPs) showed GU as the only bacterial dead-end metabolite without further degradation. In this study, batch experiments with activated sludge revealed biodegradability of GU. GU degradation was much faster under anaerobic than under aerobic conditions. Degradation kinetics for MF was much slower under anaerobic conditions. Adsorptive removal of up to 20% was an additional elimination process of MF and GU. The batch experiments were conducted with sludge of 2 WWTPs, WWTP 1 showed decreasing concentrations of GU from influent to effluent and the other increasing concentrations. This indicates a different adaption of the sludge to GU and may explain the better GU degradation capability of the sludge from WWTP 1. Furthermore, the biodegradation potential of MF was confirmed and in addition, occurrence of the TPs methylbiguanide (MBG), 2-amino-4-methylamino-1,3,5-triazine (2,4-AMT) and the secondary TP 2,4-diamino-1,3,5-triazine (2,4-DAT) was observed in batch experiments with activated sludge of WWTP 1. After fast formation, degradation in turn was slower, especially for 2,4-AMT. In general, TPs played a minor role in MF and GU degradation. Graphical abstract Image 1 Highlights • Guanyl urea revealed as biodegradable under anaerobic and aerobic conditions. • Degradation capability of guanyl urea in lab experiments is also reflected in full-scale plants. • Other transformation products of metformin were formed below 2%. [ABSTRACT FROM AUTHOR]

The aim of this work was to investigate the occurrence and fate of the antidiabetic metformin (MF) and its transformation products (TPs) in wastewater and surface water samples. New TPs of MF were approached by electrochemical degradation with a boron-doped-diamond electrode (at 1.5 V for 10 min). 2,4-Diamino-1,3,5-triazine (2,4-DAT), methylbiguanide (MBG), 2-amino-4-methylamino-1,3,5-triazine (2,4-AMT) and 4-amino-2-imino-1-methyl-1,2-dihydro-1,3,5-triazine (4,2,1-AIMT) were identified by hydrophilic interaction chromatography (HILIC) with quadrupole time-of-flight mass spectrometry (QTOF-MS) and accurate mass fragmentation. However, the well-known transformation product guanyl urea (GU) could not be formed electrochemically. In samples from wastewater treatment plants (WWTP), 2,4-AMT and 2,4-DAT showed an increasing trend from influents to effluents, which implies formation of the TPs during WWT. MBG is also formed by hydrolysis of MF and therefore didn't show this trend in WWTPs. Compared to GU, the concentrations of other TPs are generally three orders of magnitude lower. MBG and 2,4-DAT were also detected in surface water which was impacted by waste water, while 4,2,1-AIMT could not be detected in any sample. The concentrations of MF were in an expected range for influent (14 to 95 μg/l), effluent (0.7 to 6.5 μg/l), surface water (up to 234 ng/l) and tap water (34 ng/l). GU concentrations, however, were in one of the two investigated WWTP much higher in the influent (between 158 μg/l and 2100 μg/l) than in the effluent (between 26 and 810 μg/l). This is a rather unexpected result which has not been reported yet. Obviously, GU has been already formed in parts of the sewer system from MF or from other biguanide compounds like antidiabetics or disinfection chemicals. Furthermore, lower concentrations of GU in the effluents than in the influents indicate degradation processes of guanyl urea in the waste water treatment. [ABSTRACT FROM AUTHOR]

Non-target screening (NTS) based on high-resolution mass spectrometry (HRMS) is necessary to comprehensively characterize per- and polyfluoroalkyl substances (PFAS) in environmental, biological, and technical samples due to the very limited availability of authentic PFAS reference standards. Since in trace analysis, MS/MS information is not always achievable and only selected PFAS are present in homologous series, further techniques to prioritize measured HRMS data (features) according to their likelihood of being PFAS are highly desired due to the importance of efficient data reduction during NTS. Kaufmann et al. (J AOAC Int, 2022) presented a very promising approach to separate selected PFAS from sample matrix features by plotting the mass defect (MD) normalized to the number of carbons (MD/C) vs. mass normalized to the number of C (m/C). We systematically evaluated the advantages and limitations of this approach by using ~ 490,000 chemical formulas of organic chemicals (~ 210,000 PFAS, ~ 160,000 organic contaminants, and 125,000 natural organic matter compounds) and calculating how efficiently, and especially which, PFAS can be prioritized. While PFAS with high fluorine content (approximately: F/C > 0.8, H/F < 0.8, mass percent of fluorine > 55%) can be separated well, partially fluorinated PFAS with a high hydrogen content are more difficult to prioritize, which we discuss for selected PFAS. In the MD/C-m/C approach, even compounds with highly positive MDs above 0.5 Da and hence incorrectly assigned to negative MDs can still be separated from true negative mass defect features by the normalized mass (m/C). Furthermore, based on the position in the MD/C-m/C plot, we propose the estimation of the fluorine fraction in molecules for selected PFAS classes. The promising MD/C-m/C approach can be widely used in PFAS research and routine analysis. The concept is also applicable to other compound classes like iodinated compounds. [ABSTRACT FROM AUTHOR]

This review focuses on the possibilities and limits of nontarget screening of emerging contaminants, with emphasis on recent applications and developments in data evaluation and compound identification by liquid chromatography-high-resolution mass spectrometry (HRMS). The general workflow includes determination of the elemental composition from accurate mass, a further search for the molecular formula in compound libraries or general chemical databases, and a ranking of the proposed structures using further information, e.g., from mass spectrometry (MS) fragmentation and retention times. The success of nontarget screening is in some way limited to the preselection of relevant compounds from a large data set. Recently developed approaches show that statistical analysis in combination with suspect and nontarget screening are useful methods to preselect relevant compounds. Currently, the unequivocal identification of unknowns still requires information from an authentic standard which has to be measured or is already available in user-defined MS/MS reference databases or libraries containing HRMS spectral information and retention times. In this context, we discuss the advantages and future needs of publicly available MS and MS/MS reference databases and libraries which have mostly been created for the metabolomic field. A big step forward has been achieved with computer-based tools when no MS library or MS database entry is found for a compound. The numerous search results from a large chemical database can be condensed to only a few by in silico fragmentation. This has been demonstrated for selected compounds and metabolites in recent publications. Still, only very few compounds have been identified or tentatively identified in environmental samples by nontarget screening. The availability of comprehensive MS libraries with a focus on environmental contaminants would tremendously improve the situation. [ABSTRACT FROM AUTHOR]

Abstract: There is little quantitative information on the temporal trends of pharmaceuticals and other emerging compounds, including artificial sweeteners, in urban groundwater and their suitability as tracers to inform urban water management. In this study, pharmaceuticals and artificial sweeteners were monitored over 6years in a shallow urban groundwater body along with a range of conventional sewage tracers in a network of observation wells that were specifically constructed to assess sewer leakage. Out of the 71 substances screened, 24 were detected at above the analytical detection limit. The most frequent compounds were the iodinated X-ray contrast medium amidotrizoic acid (35.3%), the anticonvulsant carbamazepine (33.3%) and the artificial sweetener acesulfame (27.5%), while all other substances occurred in less than 10% of the screened wells. The results from the group of specifically constructed focus wells within 10m of defective sewers confirmed sewer leaks as being a major entrance pathway into the groundwater. The spatial distribution of pharmaceuticals and artificial sweeteners corresponds well with predictions by pipeline leakage models, which operate on optical sewer condition monitoring data and hydraulic information. Correlations between the concentrations of carbamazepine, iodinated X-ray contrast media and artificial sweeteners were weak to non-existent. Peak concentrations of up to 4130ng/l of amidotrizoic acid were found in the groundwater downstream of the local hospital. The analysis of 168 samples for amidotrizoic acid, taken at 5 different occasions, did not show significant temporal trends for the years 2002–2008, despite changed recommendations in the medical usage of amidotrizoic acid. The detailed results show that the current mass balance approaches for urban groundwater bodies must be adapted to reflect the spatially distributed leaks and the variable wastewater composition in addition to the lateral and horizontal groundwater fluxes. [Copyright &y& Elsevier]

Potentiostatic-controlled electrochemical reduction of iomeprol was used to deiodinate iomeprol (IMP), a representative of the iodinated X-ray contrast media. The reduction process was followed by product analysis with liquid chromatography-electrospray ionization-tandem mass spectrometry and ion chromatography-inductively coupled plasma-mass spectrometry. The identification is mainly based on the interpretation of the mass fragmentation. The product analysis showed a rather selective deiodination process with the successive occurrence of IMP-I, IMP-2I, IMP-3I, and a transformation product (TP), respectively. The TP was formed from IMP-3I by a further cleavage of an amide bond and release of a (C = O)CHOH group from the side chain of IMP. The iodine mass balance on the basis of IMP and iodide showed a gap of about 26% at the beginning of the electrolysis process which could be completely closed by taking the intermediates IMP-I and IMP-2I into consideration. This means that the major intermediates and the TPs were considered and that the reduction process is a rather selective one to remove organically bound iodine from X-ray contrast media. An attractive application area would be the electrochemical deiodination of X-ray contrast media in urine of patients or hospital effluents. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Disinfection is mandatory for swimming pools: public pools are usually disinfected by gaseous chlorine or sodium hypochlorite and cartridge filters; home pools typically use stabilized chlorine. These methods produce a variety of disinfection byproducts (DBPs), such as trihalomethanes (THMs), which are regulated carcinogenic DBPs in drinking water that have been detected in the blood and breath of swimmers and of nonswimmers at indoor pools. Also produced are halogenated acetic acids (HAAs) and haloketones, which irritate the eyes, skin, and mucous membranes; trichloramine, which is linked with swimming- pool-associated asthma; and halogenated derivatives of UV sun screens, some of which show endocrine effects. Precursors of DBPs include human body substances, chemicals used in cosmetics and sun screens, and natural organic matter. Analytical research has focused also on the identification of an additional portion of unknown DBPs using gas chromatography (GC)/mass spectrometry (MS) and liquid chromatography (LC)/MS/MS with derivatization. Children swimmers have an increased risk of developing asthma and infections of the respiratory tract and ear. A 1.6-2.0-fold increased risk for bladder cancer has been associated with swimming or showering/bathing with chlorinated water. Bladder cancer risk from THM exposure (all routes combined) was greatest among those with the GSTT1-1 gene. This suggests a mechanism involving distribution of THMs to the bladder by dermal/inhalation exposure and activation there by GSTT1-1 to mutagens. DBPs maybe reduced by engineering and behavioral means, such as applying new oxidation and filtration methods, reducing bromide and iodide in the source water, increasing air circulation in indoor pools, and assuring the cleanliness of swimmers. The positive health effects gained by swimming can be increased by reducing the potential adverse health risks. [ABSTRACT FROM AUTHOR]

Abstract: Interactions between dissolved organic substances (dissolved organic matter and two model substances), ions (Na+ and Ca2+) and the membrane surface were investigated using a submerged membrane module. The membrane permeability, the fouling formation and the rejection were significantly influenced by the solution’s ionic strength and especially by the presence of calcium ions. An increase of the ionic strength led to a decrease of the DOMrejection of the membrane from 75% to about 50% if Na+-ions were added and to about 15% if Ca2+-ions were added. This was due to neutralization of charges of the membrane surface and due to shielding of negative charges of DOM molecules. The ionic strength and pH of the cation solutions were kept at similar values. As the solution ionic strength increases, DOM molecules can permeate more easily through the membrane pores, since their shape and molecular size change. Adsorption of DOM on the membrane surface and in the membrane pores was only observed by filtration of solutions with Ca2+. The results showed that in the presence of Ca2+, adsorption played a mayor role in flux decline and fouling formation. [Copyright &y& Elsevier]

Abstract: Current research indicates that much of the unidentified fraction of drinking water disinfection by-products (DBPs) is highly polar and of high molecular weight. The combination of liquid chromatography and mass spectrometry (LC–MS) is being increasingly used for the direct analysis of these highly polar, hydrophilic DBPs and for the exploration of high molecular weight by-products. Further, improvements in LC–MS instrumentation and analytical techniques are providing low μg/L and ng/L detection limits, which allow trace levels of DBPs to be measured. This review covers recent applications of LC–MS and other related techniques, such as flow injection-atmospheric pressure chemical ionization and electrospray ionization (ESI)-MS, high-field asymmetric waveform ion mobility spectrometry–ESI–MS, membrane-introduction MS, and ion chromatography–ESI–MS for measuring known DBPs and exploring the nature of previously uncharacterized DBPs. [Copyright &y& Elsevier]

Environmental contaminants of recent concern are pharmaceuticals, estrogens and other endocrine disrupting chemicals (EDC) such as degradation products of surfactants, algal and cyanobacterial toxins, disinfection by-products (DBPs) and metalloids. In addition, pesticides (especially their transformation products), microorganisms, and humic substances (HS), in their function as vehicles for contaminants and as precursors for by-products in water treatment, traditionally play an important role. The present status of the application of LC-MS techniques for these water constituents are discussed and examples of application are given. Solid-phase extraction with various non-selective materials in combination with liquid chromatography (LC) on reversed-phase columns have been the most widely used methods for sample preconcentration and separation for different compound classes like pesticides, pharmaceuticals or estrogens. Electrospray ionization (ESI) and atmospheric pressure ionization (APCI) are the most frequently used ionization techniques for polar and ionic compounds, as well as for less polar non-ionic ones. The facilities of LC-MS have been successfully demonstrated for different compound classes. Polar compounds from pharmaceuticals used as betablockers, iodinated X-ray contrast media, or estrogens have been determined without derivatization down to ultratrace concentrations. LC-MS can be viewed as a prerequisite for the determination of algal and cyanobacterial toxins and the homologues and oligomers of alkylphenol ethoxylates and their metabolites. Tandem mass spectrometric techniques and the use of diagnostic ions reveal their usefulness for compound-class specific screening and unknown identification, and are also valid for the analysis of pesticides and especially for their transformation products. Structural information has been gained by the application of LC-MS methods to organometallic species. New insights into the structural variety of humic substances have been made possible by FT-ICR-MS due to its ultrahigh mass resolution. Finally, exciting possibilities for rapid detection and identification of microorganisms have been made possible by MALDI and LC-MS methods. [ABSTRACT FROM AUTHOR]

LC-MS has become an invaluable technique for trace analysis of polar compounds in aqueous samples of the environment and in water treatment. LC-MS is of particular importance due to the impetus it has provided for research into the occurrence and fate of polar contaminants, and of their even more polar transformation products. Mass spectrometric detection and identification is most widely used in combination with sample preconcentration, chromatographic separation and atmospheric pressure ionization (API). The focus of the first part of this review is directed particularly toward instruments and method development with respect to their applications for detecting emerging contaminants, microorganisms and humic substances (HS). The current status and future perspectives of 1) mass analyzers, 2) ionization techniques to interface liquid chromatography (LC) with mass spectrometry (MS), 3) methods for preconcentration and separation with respect to their application for water analysis are discussed and examples of applications are given. Quadrupole and ion trap mass analyzers with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) are already applied in routine analysis. Time-of-flight (TOF) mass spectrometers are of particular interest for accurate mass measurements for identification of unknowns. For non-polar compounds, different ionization approaches have been described, such as atmospheric pressure photoionization (APPI), electrochemistry with ESI, or electron capture ionization with APCI. In sample preconcentration and separation, solid phase extraction (SPE) with different non-selective sorbent materials and HPLC on reversed-phase materials (RP-HPLC) play the dominant role. In addition, various on-line and miniaturized approaches for sample extraction and sample introduction into the MS have been used. Ion chromatography (IC), size-exclusion chromatography (SEC), and capillary electrophoresis (CE) are alternative separation techniques. Furthermore, the issues of compound identification, matrix effects on quantitation, development of mass spectral libraries and the topic of connecting analysis and toxicity bioassays are addressed. [ABSTRACT FROM AUTHOR]

A liquid chromatography (LC) method followed by electrospray ionization (ESI) and tandem mass spectrometry (MS–MS) was developed for the quantification of acidic naphthalene derivatives in the concentration range 0.1 to 100 μg/l without excessive sample preparation. For optimal sensitivity the LC–MS–MS measurements were performed recording mass fragmentation by collision induced dissociation in the multiple reaction mode. The collision energy was optimized for every analyte. The matrix effects of the sample were investigated by spiking standards of 1-naphthoic acid with humic acid (HA) and with calcium chloride. While HA decreased the signal intensity an increase was observed in the presence of calcium chloride. For the investigated groundwater samples of a tar oil contaminated site a complete separation of the analytes from the sample matrix by reversed-phase separation could be obtained. The absence of matrix effects on quantification results was confirmed by comparison of results based on external calibration with those based on standard addition of the analytes to a groundwater sample. In four groundwater samples of the contaminated site naphthalene derivatives like 1-naphthoic acid, 2-naphthoic acid, 1-naphthylacetic acid, 2-naphthylacetic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid, and naphthyl-2-methylenesuccinic acid have been detected. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are a huge group of anthropogenic chemicals with unique properties that are used in countless products and applications. Due to the high stability of their C-F bonds, PFAS or their transformation products (TPs) are persistent in the environment, leading to ubiquitous detection in various samples worldwide. Since PFAS are industrial chemicals, the availability of authentic PFAS reference standards is limited, making non-target screening (NTS) approaches based on high-resolution mass spectrometry (HRMS) necessary for a more comprehensive characterization. NTS usually is a time-consuming process, since only a small fraction of the detected chemicals can be identified. Therefore, efficient prioritization of relevant HRMS signals is one of the most crucial steps. We developed PFΔScreen, a Python-based open-source tool with a simple graphical user interface (GUI) to perform efficient feature prioritization using several PFAS-specific techniques such as the highly promising MD/C-m/C approach, Kendrick mass defect analysis, diagnostic fragments (MS2), fragment mass differences (MS2), and suspect screening. Feature detection from vendor-independent MS raw data (mzML, data-dependent acquisition) is performed via pyOpenMS (or custom feature lists) with subsequent calculations for prioritization and identification of PFAS in both HPLC- and GC-HRMS data. The PFΔScreen workflow is presented on four PFAS-contaminated agricultural soil samples from south-western Germany. Over 15 classes of PFAS (more than 80 single compounds with several isomers) could be identified, including four novel classes, potentially TPs of the precursors fluorotelomer mercapto alkyl phosphates (FTMAPs). PFΔScreen can be used within the Python environment and is easily automatically installable and executable on Windows. Its source code is freely available on GitHub (https://github.com/JonZwe/PFAScreen). [ABSTRACT FROM AUTHOR]

Temperature and soil moisture are known to control pesticide mineralization. Half‐life times (DT50$$ {DT}_{50} $$) derived from pesticide mineralization curves generally indicate longer residence times at low soil temperature and moisture but do not consider potential changes in the microbial allocation of pesticide‐derived carbon (C). We aimed to determine carbon use efficiency (CUE$$ CUE $$, formation of new biomass relative to total C uptake) to better understand microbial utilization of pesticide‐derived C under different environmental conditions and to support the conventional description of degradation dynamics based on mineralization. We performed a microcosm experiment at two MCPA (2‐methyl‐4‐chlorophenoxyacetic acid) concentrations (1 and 20 mg kg−1) and defined 20°C/pF 1.8 as optimal and 10°C/pF 3.5 as limiting environmental conditions. After 4 weeks, 70% of the initially applied MCPA was mineralized under optimal conditions but MCPA mineralization reached less than 25% under limiting conditions. However, under limiting conditions, an increase in CUE$$ CUE $$ was observed, indicating a shift towards anabolic utilization of MCPA‐derived C. In this case, increased C assimilation implied C storage or the formation of precursor compounds to support resistance mechanisms, rather than actual growth since we did not find an increase in the tfdA gene relevant to MCPA degradation. We were able to confirm the assumption that under limiting conditions, C assimilation increases relative to mineralization and that C redistribution, may serve as an explanation for the difference between mineralization and MCPA dissipation‐derived degradation dynamics. In addition, by introducing CUE$$ CUE $$ to the temperature‐ and moisture‐dependent degradation of pesticides, we can capture the underlying microbial constraints and adaptive mechanisms to changing environmental conditions. [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented in which the guest editor discusses analytical techniques and methods in environmental and geosciences.

High per- and polyfluorinated alkyl substance (PFAS) concentrations have been detected in agricultural soils in Southwest Germany. Discharges of PFAS-contaminated paper sludge and compost are suspected to be the cause of the contamination. Perfluorinated carboxylic acids (PFCAs) have been detected also in groundwater, drinking water, and plants in this area. Recently, previously unknown compounds have been identified by high-resolution mass spectrometry (HRMS). Major contaminants were polyfluorinated dialkylated phosphate esters (diPAPs) and N-ethyl perfluorooctane sulfonamide ethanol–based phosphate diester (diSAmPAP). In this study, HRMS screening for PFAS was applied to 14 soil samples from the contaminated area and 14 impregnated paper samples which were from a similar period than the contamination. The paper samples were characterized by diPAPs (from 4:2/6:2 to 12:2/12:2), fluorotelomer mercapto alkyl phosphates (FTMAPs; 6:2/6:2 to 10:2/10:2), and diSAmPAP. In soil samples, diPAPs and their transformation products (TPs) were the major contaminants, but also FTMAPs, diSAmPAP, and their TPs occurred. The distribution patterns of the carbon chain lengths of the precursor PFAS in soil samples were shown to resemble those in paper samples. This supports the hypothesis that paper sludge is a major source of contamination. The presence of major degradation products like PFCAs, FTSAs, or PFOS and their distribution of carbon chain lengths indicate the activity of biotic or abiotic degradation processes and selective leaching processes from the upper soil horizons. [ABSTRACT FROM AUTHOR]

The anaerobic microbial degradation of aromatic and heterocyclic compounds is a prevalent process in contaminated groundwater systems. The introduction of functional groups into the contaminant molecules often results in aromatic and heterocyclic and succinic acids. These metabolites can be used as indicators for prevailing degradation processes. Therefore, there is a strong interest in developing analytical methods for screening and identification of these metabolites. In this study, neutral loss scans (NLS) by liquid chromatography-electrospray ionization/tandem mass spectrometry with losses of CO (NL ∆ m/ z = 44) and CH(CO) (NL ∆ m/ z = 116) were applied for the first time successfully to screen selectively for acidic and succinic metabolites of aromatic and heterocyclic contaminants in two fulvic acid fractions from a contaminated site and a downstream region of a tar oil-polluted groundwater. Identification of these preselected signals was performed by high-resolution mass spectrometry with a liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry instrument. High-resolution mass and mass fragmentation data were then compared with a list of known metabolites from a literature search or matched with chemical databases supported with in silico fragmentation. Based on authentic analytical standards, several compounds from NLS were identified (e.g., 4-hydroxy-3-methylbenzoic acid, benzylsuccinic acid, naphthyl-2-methylsuccinic acid, 2-carboxyindane, and 2-carboxybenzothiophene) and tentatively identified (e.g., benzofuranmethylsuccinic acid and dihydrocarboxybenzothiophene) as aromatic, phenolic, heterocyclic, and succinic acids. The acidic metabolites were found exclusively in the contaminated region of the aquifer which indicates active biodegradation processes and no relevant occurrence of acidic metabolites in the downstream region. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Trichloramine is a volatile, irritant compound of penetrating odor, which is found as a disinfection by-product in the air of chlorinated indoor swimming pools from reactions of nitrogenous compounds with chlorine. Acid amides, especially urea, ammonium ions and α-amino acids have been found as most efficient trichloramine precursors at acidic and neutral pH. For urea a relative NCl3 formation of 96% at pH 2.5 and 76% at pH 7.1 was determined. Even under sub-stoichiometric molar ratios of Cl/N the formation of NCl3 is favored over mono and dichlorinated products. However, the reaction kinetics of urea with chlorine is slow under conditions relevant for swimming pools. Also the mass transfer of NCl3 from water to the gas phase which was calculated by the Deacon’s boundary layer model could be shown as a relatively slow process. Mass transfer would take 20 h or 5.8 d for a rough or a quiescent surface of the water, respectively. This is much more than a typical turnover rate of 6–8 h of a treatment cycle of a 25 m swimming pool. Therefore processes to remove NCl3 and its precursors can help to minimize the exposure of bathers. [Copyright &y& Elsevier]

A correction to the article "Mass spectrometric screening and identification of acidic metabolites in fulvic acid fractions of contaminated groundwater" that was published in the previous issue is presented.

Organic micropollutants of anthropogenic origin in river waters may impair aquatic ecosystem health and drinking water quality. To evaluate micropollutant fate and turnover on a catchment scale, information on input source characteristics as well as spatial and temporal variability is required. The influence of tributaries from agricultural and urban areas and the input of wastewater were investigated by grab and Lagrangian sampling under base flow conditions within a 7.7‐km‐long stretch of the Ammer River (southwest Germany) using target screening for 83 organic micropollutants and 4 in vitro bioassays with environmentally relevant modes of action. In total, 9 pesticides and transformation products, 13 pharmaceuticals, and 6 industrial and household chemicals were detected. Further, aryl hydrocarbon receptor induction, peroxisome proliferator–activated receptor activity, estrogenicity, and oxidative stress response were measured in the river. The vast majority of the compounds and mixture effects were introduced by the effluent of a wastewater‐treatment plant, which contributed 50% of the total flow rate of the river on the sampling day. The tributaries contributed little to the overall load of organic micropollutants and mixture effects because of their relatively low discharge but showed a different chemical and toxicological pattern from the Ammer River, though a comparison to effect‐based trigger values pointed toward unacceptable surface water quality in the main stem and in some of the tributaries. Chemical analysis and in vitro bioassays covered different windows of analyte properties but reflected the same picture. Environ Toxicol Chem 2020;39:1382–1391. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

BACKGROUND: Trihalomethanes (THMs) are widespread disinfection by-products (DBPs) in drinking water, and long-term exposure has been consistently associated with increased bladder cancer risk. OBJECTIVE: We assessed THM levels in drinking water in the European Union as a marker of DBP exposure and estimated the attributable burden of bladder cancer. METHODS: We collected recent annual mean THM levels in municipal drinking water in 28 European countries (EU28) from routine monitoring records. We estimated a linear exposure–response function for average residential THM levels and bladder cancer by pooling data from studies included in the largest international pooled analysis published to date in order to estimate odds ratios (ORs) for bladder cancer associated with the mean THM level in each country (relative to no exposure), population-attributable fraction (PAF), and number of attributable bladder cancer cases in different scenarios using incidence rates and population from the Global Burden of Disease study of 2016. RESULTS: We obtained 2005-2018 THM data from EU26, covering 75% of the population. Data coverage and accuracy were heterogeneous among countries. The estimated population-weighted mean THM level was 11.7 &#956g/L [standard deviation (SD) of 11.2]. The estimated bladder cancer PAF was 4.9% [95% confidence interval (CI): 2.5, 7.1] overall (range: 0-23%), accounting for 6,561 (95% CI: 3,389, 9,537) bladder cancer cases per year. Denmark and the Netherlands had the lowest PAF (0.0% each), while Cyprus (23.2%), Malta (17.9%), and Ireland (17.2%) had the highest among EU26. In the scenario where no country would exceed the current EU mean, 2,868 (95% CI: 1,522, 4,060; 43%) annual attributable bladder cancer cases could potentially be avoided. DISCUSSION: Efforts have been made to reduce THM levels in the European Union. However, assuming a causal association, current levels in certain countries still could lead to a considerable burden of bladder cancer that could potentially be avoided by optimizing water treatment, disinfection, and distribution practices, among other possible measures. [ABSTRACT FROM AUTHOR]

Denatonium, one of the bitterest substances known to man, was recently identified as wastewater borne micropollutant in surface waters. Therefore, photodegradation experiments and electrochemical degradation were performed to identify abiotic and putative biotic transformation products (TPs). Indirect rather than direct photodegradation proved to be important for denatonium removal by solar irradiation and produced seven TPs. Amide hydrolysis, hydroxylation, N-dealkylation, and N-dearylation were revealed as the main mechanisms. Anodic oxidation of denatonium was related to the formation of overall ten products and despite considerable different yields, all TPs from indirect photodegradation were mimicked electrochemically. Among them, lidocaine was the only TP detected after conventional wastewater treatment and in surface waters. The occurrence of lidocaine was however associated with its application as local anesthetic rather than to a degradation of denatonium. The absence of additional products suggests that denatonium degradation is negligible under environmental conditions, supporting the previously described persistent nature of this compound. Advanced water treatment techniques however have the potential to degrade denatonium. About 74% of the initial denatonium load was removed from wastewater during pilot-scale ozonation. The degradation of denatonium was accompanied here with the formation of at least two polar products, which are passing unchanged through a sand filter after ozonation. Both substances have completely unknown (toxicological) properties and this study seems to be the first report about their structures in general, as none of them was found in any of the large compound libraries (e.g. PubChem). Unlabelled Image • Indirect photodegradation and electrochemical oxidation resulted in overall ten TPs. • Five products were identified with a confidence level of 2 or better. • High persistence of denatonium in conventional wastewater treatment and in surface waters observed. • Denatonium removal by ozonation is associated with the formation of polar TPs. [ABSTRACT FROM AUTHOR]

Some environmental pollutants impair mitochondria, which are of vital importance as energy factories in eukaryotic cells. Mitochondrial toxicity was quantified by measuring the change of the oxygen consumption rate (OCR) of HepG2 cells with the Agilent Seahorse XFe96 Analyzer. Various mechanisms of mitochondrial toxicity, including inhibition of the electron transport chain or adenosine triphosphate (ATP) synthase as well as uncoupling of oxidative phosphorylation, were differentiated by dosing the sample in parallel with reference compounds following the OCR over time. These time–OCR traces were used to derive effect concentrations for 10% inhibition of the electron transport chain or 10% of uncoupling. The low effect level of 10% was necessary because environmental mixtures contain thousands of chemicals; only few of them interfere with mitochondria, but the others cause cytotoxicity. The OCR bioassay was validated with environmental pollutants of known mechanism of mitochondrial toxicity. Binary mixtures of uncouplers or inhibitors acted according to the mixture model of concentration addition. Uncoupling and/or inhibitory effects were detected in extracts of river water samples without apparent cytotoxicity. Uncoupling effects could only be quantified in water samples if inhibitory effects occurred at lower concentrations because no uncoupling can be detected without an appreciable membrane potential built up. The OCR bioassay can thus complement chemical analysis and in vitro bioassays for monitoring micropollutants in water. Environ Toxicol Chem 2019;00:1–12. © 2019 SETAC [ABSTRACT FROM AUTHOR]

Abstract Interpreting the fate of wastewater contaminants in streams is difficult because their inputs vary in time and several processes synchronously affect reactive transport. We present a method to disentangle the various influences by performing a conservative-tracer test while sampling a stream section at various locations for chemical analysis of micropollutants. By comparing the outflow concentrations of contaminants with the tracer signal convoluted by the inflow time series, we estimated reaction rate coefficients and calculated the contaminant removal along a river section. The method was tested at River Steinlach, Germany, where 38 contaminants were monitored. Comparing day-time and night-time experiments allowed distinguishing photo-dependent degradation from other elimination processes. While photo-dependent degradation showed to be highly efficient for the removal of metroprolol, bisoprolol, and venlafaxine, its impact on contaminant removal was on a similar scale to the photo-independent processes when averaged over 24 h. For a selection of compounds analyzed in the present study, bio- and photodegradation were higher than in previous field studies. In the Steinlach study, we observed extraordinarily effective removal processes that may be due to the higher proportion of treated wastewater, temperature, DOC and nitrate concentrations, but also a higher surface to volume ratio from low flow conditions that favorizes photodegradation through the shallow water column and a larger transient storage than observed in comparable studies. Graphical abstract Unlabelled Image Highlights • Studying reactive processes in river channels is inherently difficult. • Tracer tests allowed separating conservative transport from the measured signal. • Comparison of day and night experiments highlighted photodegradation. • Photodegradation is weaker than photo-independent elimination on the long term. [ABSTRACT FROM AUTHOR]

Abstract β‑Lactam antibiotics are among the most widely used antibiotics in human medicine and their effects on the aquatic environment - concerning bacterial resistance - are controversially discussed. This study focused on the photolysis of the four β‑lactam antibiotics - amoxicillin, ampicillin, penicillin V and piperacillin - under simulated environmental conditions. It was observed that all investigated β‑lactam antibiotics are photolytically degradable by simulated sunlight (1 kW/m2) with half-lives between 3.2 and 7.0 h. Structure elucidation of transformation products performed with liquid chromatography coupled to high resolution mass spectrometry showed that the hydrolysis of the β‑lactam ring is the primary transformation reaction, followed by the elimination of carboxylic and dimethyl thiazolidine carboxylic acid. Growth inhibition tests on Bacillus subtilis showed the loss of bactericide activity of irradiated solutions of amoxicillin, ampicillin and piperacillin, suggesting the transformation of the β‑lactam ring is responsible for the antibiotic effect. In contrast, the solutions of penicillin V did not show any decline of the antibacterial activity after photolytic degradation, probably due to the formation of still active epimers. Graphical abstract Unlabelled Image Highlights • Simulated sunlight was shown to be able to degrade β‑lactam antibiotics. • New transformation products of β‑lactam antibiotics were elucidated. • Photolysis of amoxicillin, ampicillin and piperacillin reduces the growth inhibition effect. • Photolytically transformed penicillin V keeps the ability to inhibit bacterial growth. [ABSTRACT FROM AUTHOR]

The discovery of new disinfection by-products (DBPs) is still a rarely investigated research area in past studies. In particular, compared to freshwater pools, therapeutic pools with their unique chemical composition have rarely been investigated for novel DBPs. Here we have developed a semi-automated workflow that combines data from target and non-target screening, calculated and measured toxicities into a heat map using hierarchical clustering to assess the pool's overall potential chemical risk. In addition, we used complementary analytical techniques such as positive and negative chemical ionization to demonstrate how novel DBPs can be better identified in future studies. We identified two representatives of the haloketones (pentachloroacetone, and pentabromoacetone) and tribromo furoic acid detected for the first time in swimming pools. Non-target screening combined with target analysis and toxicity assessment may help to define risk-based monitoring strategies in the future, as required by regulatory frameworks for swimming pool operations worldwide. [Display omitted] • Use of EI, PCI and NCI as complementary analytical methods. • Identification of potential toxic DBPs by GC/LC-HRMS. • Hierarchical clustering for analysis of non-target features. • Application of suspect and non-target screening approaches to detect DBPs. • Identification of two new haloketones and tribromo furoic acid in swimming pools. [ABSTRACT FROM AUTHOR]

Background Exposure to disinfection by-products (DBPs) in drinking water and chlorinated swimming pools are associated with adverse health outcomes, but biological mechanisms remain poorly understood. Objectives Evaluate short-term changes in metabolic profiles in response to DBP exposure while swimming in a chlorinated pool. Materials and methods The PISCINA-II study (EXPOsOMICS project) includes 60 volunteers swimming 40 min in an indoor pool. Levels of most common DBPs were measured in water and in exhaled breath before and after swimming. Blood samples, collected before and 2 h after swimming, were used for metabolic profiling by liquid-chromatography coupled to high-resolution mass-spectrometry. Metabolome-wide association between DBP exposures and each metabolic feature was evaluated using multivariate normal (MVN) models. Sensitivity analyses and compound annotation were conducted. Results Exposure levels of all DBPs in exhaled breath were higher after the experiment. A total of 6,471 metabolic features were detected and 293 features were associated with at least one DBP in exhaled breath following Bonferroni correction. A total of 333 metabolic features were associated to at least one DBP measured in water or urine. Uptake of DBPs and physical activity were strongly correlated and mutual adjustment reduced the number of statistically significant associations. From the 293 features, 20 could be identified corresponding to 13 metabolites including compounds in the tryptophan metabolism pathway. Conclusion Our study identified numerous molecular changes following a swim in a chlorinated pool. While we could not explicitly evaluate which experiment-related factors induced these associations, molecular characterization highlighted metabolic features associated with exposure changes during swimming. [ABSTRACT FROM AUTHOR]

Background Exposure to disinfectants and disinfection byproducts (DBPs) due to swimming in chlorinated water has been associated with allergic and respiratory health effects, including asthma. Objectives Biological mechanisms contributing to these associations are largely unknown. We hypothesized a potential pathway involving modulation of the immune system. Methods We assessed levels of immune markers (CCL11, CCL22, CXCL10, CRP, EGF, GCSF, IL-8, IL-17, IL-1RA, MPO, VEGF, Periostin) in serum collected from 30 women and 29 men before and after 40 min of swimming in a chlorinated pool. Exposure to DBPs was assessed by measuring bromodichloromethane, bromoform, chloroform, and dibromochloromethane in exhaled breath before and after swimming. Covariate data including information on physical activity was available through questionnaires and measurements. We assessed the association between indicators of swimming in a chlorinated pool and changes in serum immune marker concentrations using linear regression with bivariate normal distributions and adjusted for multiple comparisons by applying the Benjamini-Hochberg procedure. Results We observed a significant decrease in serum concentrations of IL-8 (− 12.53%; q = 2.00e-03), CCL22 (− 7.28%; q = 4.00e-04), CCL11 (− 7.15%; q = 9.48e-02), CRP (− 7.06%; q = 4.68e-05), and CXCL10 (− 13.03%; q = 6.34e-14) and a significant increase in IL-1RA (20.16%; q = 4.18e-06) from before to after swimming. Associations with quantitative measurements of DBPs or physical activity were similar in direction and strength. Most of the observed associations became non-significant when we adjusted the effects of exposure to DBPs for physical activity or vice-versa. Conclusions Our study indicates that swimming in a chlorinated pool induces perturbations of the immune response through acute alterations of patterns of cytokine and chemokine secretion. The observed effects could not be uniquely attributed to either exposure to DBPs or physical activity. Evidence in the literature suggests that observed decreases in immune markers are possibly due to an immunosuppressive effect of DBPs, while the increase in IL-1RA might be due to physical activity. [ABSTRACT FROM AUTHOR]

Denatonium is one of the bitterest substances known to man and therefore applied in numerous consumer products to prevent an accidental or intentional consumption. So far no information was available on the occurrence of this compound in the environment. A sensitive targeted method was developed and applied to water samples taken in the federal state of Baden-Württemberg, Germany. Denatonium was detected in 100% of the investigated 22 wastewater treatment plant (WWTP) effluents with a maximum concentration of 341 ng L −1 . Additionally, water samples were taken from the Ammer river over a period of one week and all wastewater impacted samples showed denatonium at concentrations up to 195 ng L −1 . Retrospective analysis of high-resolution mass spectrometric measurements of WWTP effluents from Italy and Switzerland confirmed and therefore point to an international occurrence of denatonium as anthropogenic contaminant. [ABSTRACT FROM AUTHOR]

Worldwide, ozonation of secondary wastewater effluents is increasingly considered in order to decrease the load of organic contaminants before environmental discharge. However, despite the constantly growing knowledge of ozonation over the past few years, the characterization of transformation products (TPs) is still a major concern, particularly because such TPs might remain biologically active. It has been shown for selected tertiary amine pharmaceuticals that they react with ozone and form the corresponding N-oxides. This study therefore applies liquid chromatography-high resolution mass spectrometry (LC-HRMS) to assess the overall N-oxide formation during the pilot-scale ozonation of a secondary wastewater effluent from a major city in Germany. Sample analysis by LC-HRMS revealed the occurrence of 1,229 compounds, among which 853 were precursors attenuated by ozone and 165 were TPs. Further examination of precursors and TPs using Kendrick mass and Kendrick mass defect analysis revealed 34 pairs of precursors and products corresponding to a mono-oxygenation. Among these, 27 pairs (16% of all TPs) were consistent with N-oxides since the TP had a higher retention time than the precursor, a characteristic of these compounds. Using high resolution tandem mass spectrometry, 10 of these N-oxides could be identified and were shown to be stable during a subsequent filtration step. [ABSTRACT FROM AUTHOR]

Carbon nanotube (CNT) membranes were produced from multi-walled CNTs by a filtration technique and used for the removal of the betablocker metoprolol by adsorptive and reactive processes. The reactivity of CNT membranes was enhanced by nanoparticulate zero-valent iron (NZVI) which was deposited on the CNT membranes by pulsed voltammetry applying defined number of pulses (Fe-CNT (100) and Fe-CNT (400) membranes). Surface analysis with SEM showed iron nanoparticle sizes between 19 and 425 nm. Pore size distribution for the different membranes was determined by capillary flow porometry (Galwick fluid). Pore size distribution for all membranes was similar (40 nm), which resulted in a water permeability typical for microfiltration membranes. Metoprolol was removed by the CNT membrane only by sorption, whereas the Fe-CNT membrane revealed also metoprolol degradation due to Fenton type reactions. Further application of electrochemical potentials on both the CNT and the Fe-CNT membranes improved the removal efficiencies to 74% for CNT membranes at 1 V and to 97% for Fe-CNT (400) membranes at 1 V. Seven transformation products have been identified for metoprolol by high-resolution mass spectrometry when electrochemical degradation was performed with CNT and Fe-CNT membranes. Additionally, two of the identified transformation products (TPs) were also observed for Fe-CNT membranes without the application of electrochemical potential. However, only 10% of the degraded metoprolol could be explained by the formation of TPs. [ABSTRACT FROM AUTHOR]

Sodium hypochlorite (NaClO) is the most commonly used disinfectant in pool treatment system. Outdoor pools usually suffer from the strong sunlight irradiation which degrades the free chlorine rapidly. In addition, more pools start to adopt the recirculation of swimming pool water, which intensifies the disinfection by-product (DBP) accumulation issue. Given these potential drawbacks of using NaClO in the tropical environment, two alternative organic-based disinfectants, trichloroisocyanuric acid (TCCA, C 3 Cl 3 N 3 O 3 ) and bromochlorodimethylhydantoin (BCDMH, C 5 H 6 BrClN 2 O 2 ), were investigated and compared to NaClO in terms of their self-degradation and the formation of DBPs, including trihalomethanes (THMs) and haloacetic acids (HAAs), under simulated tropical climate conditions. The result reveals that halogen stabilizer, TCCA, had the advantages of slower free chlorine degradation and lower DBP concentration compared to NaClO, which makes it a good alternative disinfectant. BCDMH was not recommended mainly due to the highly reactive disinfecting ingredient, hypobromous acid (HBrO), which fails to sustain the continuous disinfection requirement. Total disinfectant dosage was the main factor that affects residual chlorine/bromine and THM/HAA formation regardless of different disinfectant dosing methods, e.g. shock dosing (one-time spiking) in the beginning, and continuous dosing during the whole experimental period. Two-stage second-order-kinetic-based models demonstrate a good correlation between the measured and predicted data for chlorine decay ( R 2 ≥ 0.95), THM ( R 2 ≥ 0.99) and HAA ( R 2 ≥ 0.83) formation. Higher temperature was found to enhance the DBP formation due to the temperature dependence of reaction rates. Thus, temperature control of pools, especially for those preferring higher temperatures (e.g. hydrotherapy and spa), should take both bather comfort and DBP formation potential into consideration. It is also observed that chlorine competition existed between different precursors from natural organic matters (NOM) in filling water and body fluid analogue (BFA). Among the composition of BFA, uric acid, citric acid and hippuric acid were found to be the main precursors for HAA formation. [ABSTRACT FROM AUTHOR]

Background Trihalomethanes (THMs) in exhaled breath and trichloroacetic acid (TCAA) in urine are internal dose biomarkers of exposure to disinfection by-products (DBPs) in swimming pools. Objective We assessed how these biomarkers reflect the levels of a battery of DBPs in pool water and trichloramine in air, and evaluated personal determinants. Methods A total of 116 adults swam during 40 min in a chlorinated indoor pool. We measured chloroform, bromodichloromethane, dibromochloromethane and bromoform in exhaled breath and TCAA in urine before and after swimming, trichloramine in air and several DBPs in water. Personal determinants included sex, age, body mass index (BMI), distance swum, energy expenditure, heart rate and 12 polymorphisms in GSTT1 , GSTZ1 and CYP2E1 genes. Results Median level of exhaled total THMs and creatinine adjusted urine TCAA increased from 0.5 to 14.4 µg/m 3 and from 2.5 to 5.8 µmol/mol after swimming, respectively. The increase in exhaled brominated THMs was correlated with brominated THMs, haloacetic acids, haloacetonitriles, haloketones, chloramines, total organic carbon and total organic halogen in water and trichloramine in air. Such correlations were not detected for exhaled chloroform, total THMs or urine TCAA. Exhaled THM increased more in men, urine TCAA increased more in women, and both were affected by exercise intensity. Genetic variants were associated with differential increases in exposure biomarkers. Conclusion Our findings suggest that, although affected by sex, physical activity and polymorphisms in key metabolizing enzymes, brominated THMs in exhaled breath could be used as a non-invasive DBP exposure biomarker in swimming pools with bromide-containing source waters. This warrants confirmation with new studies. [ABSTRACT FROM AUTHOR]

In this article, a dataset from a collaborative non-target screening trial organised by the NORMAN Association is used to review the state-of-the-art and discuss future perspectives of non-target screening using high-resolution mass spectrometry in water analysis. A total of 18 institutes from 12 European countries analysed an extract of the same water sample collected from the River Danube with either one or both of liquid and gas chromatography coupled with mass spectrometry detection. This article focuses mainly on the use of high resolution screening techniques with target, suspect, and non-target workflows to identify substances in environmental samples. Specific examples are given to emphasise major challenges including isobaric and co-eluting substances, dependence on target and suspect lists, formula assignment, the use of retention information, and the confidence of identification. Approaches and methods applicable to unit resolution data are also discussed. Although most substances were identified using high resolution data with target and suspect-screening approaches, some participants proposed tentative non-target identifications. This comprehensive dataset revealed that non-target analytical techniques are already substantially harmonised between the participants, but the data processing remains time-consuming. Although the objective of a 'fully-automated identification workflow' remains elusive in the short term, important steps in this direction have been taken, exemplified by the growing popularity of suspect screening approaches. Major recommendations to improve non-target screening include better integration and connection of desired features into software packages, the exchange of target and suspect lists, and the contribution of more spectra from standard substances into (openly accessible) databases. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Challenging tasks, increasing demands, and new generations of powerful analytical instruments initiated considerable progress in aquatic environmental analysis and led to a considerable improvement of analytical performance during the last few years. The ever growing number of emerging pollutants is tackled by specific and highly sensitive analytical methods with detection limits of a few nanogram per liter and even lower. Wide-scope monitoring techniques and multiclass and multiresidue analysis allow for the simultaneous determination of hundreds of compounds. The high mass resolution capability and mass accuracy of advanced mass spectrometric instruments, i.e., time-of-flight (TOF) MS or Fourier transform (FT)-Orbitrap MS, enable combined target and non-target analysis, including the identification of metabolites and abiotic degradation products. This minireview highlights some of the most recent developments in the trace analysis of important organic water pollutants and focuses on some specific groups of emerging contaminants, i.e., pharmaceuticals, flame retardants, disinfection by-products, surfactants, per- and polyfluorinated compounds, benzotriazoles, and benzothiazoles, as well as on the identification of transformation products and on non-target analysis. References were selected according to their exemplary and innovative character and to their practical relevance. [ABSTRACT FROM AUTHOR]

Anaerobic degradation processes play an important role in contaminated aquifers. To indicate active blodegradation processes signature metabolites can be used. In this study field samples from a high-resolution multilevel well in a tar oil-contaminated, anoxic aquifer were analyzed for metabolites by liquid chromatography-tandem mass spectrometry and time-of-flight mass spectrometry. In addition to already known specific degradation products of toluene, xylenes, and naphthalenes, the seldom reported degradation products benzothiophenemethylsuccinic acid (BTMS), benzofuranmethyl-succinic acid (BFMS), methylnaphthyl-2-methylsuccinic acid (MNMS), and acenaphthene-5-carboxylic acid (AC) could be identified (BFMS, AC) and tentatively identified (BTMS, MNMS). The occurrence of BTMS and BFMS clearly show that the tumarate addition pathway, known for toluene and methylnaph-thalene, is also important for the anaerobic degradation of heterocyclic contaminants in aquifers. The molar concentration ratios of metabolites and their related parent compounds differ over a wide range which shows that there is no simple and consistent quantitative relation. However, generally higher ratios were found for the more recalcitrant compounds, which are putatively cometabolically degraded (e.g., 2-car-boxybenzothiophene and acenaphthene-5-carboxylic acid), indicating an accumulation of these metabolites. Vertical concentration profiles of benzylsuccinic acid (BS) and methyl-benzylsuccinic acid (MBS) showed distinct peaks at the fringes of the toluene and xylene plume indicating hot spots of biodegradation activity and supporting the plume fringe concept. However, there are some compounds which show a different vertical distribution with the most prominent concentrations where also the precursor compounds peaked. [ABSTRACT FROM AUTHOR]

Abstract: Swimming pool water treatment in general includes flocculation, sand filtration, and subsequent disinfection with chlorine. The continuous chlorination and input of organic material by bathers in combination with recirculation of the pool water leads to an accumulation of disinfection by-products (DBPs) in the water. Several DBPs have been identified as human carcinogens and are thought to cause allergic asthma. Therefore, the elimination of DBPs is one major aim of pool water treatment. Using membrane filtration as an alternative treatment technology, DBPs can be removed more efficiently than with conventional treatment. In this study membrane filtration and genotoxicity testing were applied for the characterization of pool water constituents and for the identification of the necessary molecular weight cut off of the membrane for an efficient elimination. Two-step membrane filtration revealed that most of the DBPs (as adsorbable organically bound halogen, AOX) were present in the molecular weight fraction below 1000g/mol. The fraction below 200g/mol contained more than 30% of the AOX. The distribution of the dissolved organic carbon (DOC) across the fractions was similar to that of the AOX. The genotoxicity was found to be strongest in the low-molecular weight fraction. Thus, considerable DBP removal by membrane treatment requires membranes with low-molecular weight cut offs down to 200g/mol. The comprehensive elimination of the genotoxic compounds requires further treatment steps. [Copyright &y& Elsevier]

Organic micropollutants enter rivers mainly with discharges of wastewater treatment plants (WWTP) and pose a risk to aquatic ecosystems and water quality. A considerable knowledge gap exists for disentangling overlapping processes and driving conditions that control the fate of these pollutants. Thus, the aim of this study was to identify the driving parameters for attenuation of selected pharmaceuticals (carbamazepine, diclofenac, tramadol and venlafaxine) under field conditions. The presented study was performed at a small river (Ammer River, mean discharge 0.87 m3 s−1) which is hydrologically complex due to karstification, numerous artificial discharges, and engineered modifications of the channel. We applied a Lagrangian sampling scheme at two sequential river reaches. In general, for the investigated compounds and over the length of the tested reaches, the absolute net attenuation representative for 24 h was low (≤ 23% net attenuation), yet calculated half-lives were comparable to literature. Photodegradation is specifically relevant for the first river reach characterized by a higher net attenuation of the photosensitive compound diclofenac (14.5% ±11.3%) compared to the second section (9.8% ±13.7%). This is likely due to a spatial difference in canopy shading, which is supported by significant correlations (R2 ≥ 0.8) of the temporally changing 'temperature' and 'solar radiation' with time-specific degradation rate constants of photosensitive compounds for consecutive hourly water parcels. In general, the presented spatially and temporally resolved approach is a suitable tool to determine the attenuation of organic micropollutants and to narrow down the interpretation of net attenuation to a few reasonable processes. Unlabelled Image • Integrated investigation combining field approaches and chemical analysis in a small river • River water influenced by (diffuse) groundwater inflow and wastewater • Application of a mass balance approach based on Lagrangian sampling • Determination of temporal and spatial variability in attenuation of organic micropollutants • Photodegradation identified as major attenuation mechanism in the studied river [ABSTRACT FROM AUTHOR]

The pharmaceutical torasemide is an important loop diuretic and was 2017 one of the ten most prescribed drugs in Germany. Despite its detection in different compartments of the urban water cycle including drinking water, no studies were so far performed to elucidate its fate in the environment and the occurrence of transformation products (TPs). Therefore, we investigated the phototransformation, microbial degradation, transformation with human liver microsomes and anodic oxidation of torasemide to obtain good coverage of environmentally relevant degradation products. Overall sixteen products were identified, covering the following reaction mechanisms: aromatic and aliphatic hydroxylation, including further oxidation to carboxylic acids and quinone imines, amide cleavage, N-dealkylation, N-dearylation, and sulfonamide hydrolysis to sulfonic acids. Especially the formation of quinone imines could be of concern as they are highly reactive electrophiles. Torasemide itself was observed in all investigated wastewater treatment plant (WWTP) samples and wastewater-impacted surface waters. The maximum detected concentration was about 350 ng L−1. Only three of the sixteen transformation products were generally observed in at least one of the samples and the most frequently detected TPs were the human metabolites hydroxytorasemide (TP 364a) and carboxytorasemide (TP 378a). The complete removal of TP 364a during wastewater treatment was in agreement with the results of microbial degradation experiments. TP 364a was most likely transformed into TP 378a, which was microbially less degraded in lab experiments. Based on estimated concentrations, TP 378a could reach about 1 μg L−1 in the investigated wastewater matrices. Image 1 • Overall sixteen abiotic and biotic products identified for torasemide. • Formation of reactive products proven with trapping experiments using reduced glutathione. • Torasemide and carboxytorasemide detected in all WWTPs and wastewater-impacted surface waters. [ABSTRACT FROM AUTHOR]

Swimming in pools is a healthy activity that entails exposure to disinfection by-products (DBPs), some of which are irritant and genotoxic. We evaluated exposure to DBPs during swimming in a chlorinated pool and the association with short-term changes in genotoxicity and lung epithelium permeability biomarkers. Non-smoker adults (N = 116) swimming 40 min in an indoor pool were included. We measured a range of biomarkers before and at different times after swimming: trihalomethanes (THMs) in exhaled breath (5 min), trichloroacetic acid (TCAA) in urine (30 min), micronuclei in lymphocytes (1 h), serum club cell protein (CC16) (1 h), urine mutagenicity (2 h) and micronuclei in reticulocytes (4 days in a subset, N = 19). Several DBPs in water and trichloramine in air were measured, and physical activity was extensively assessed. We estimated interactions with polymorphisms in genes related to DBP metabolism. Median level of chloroform, brominated and total THMs in water was 37.3, 9.5 and 48.5, μg/L, respectively, and trichloramine in air was 472.6 μg/m3. Median exhaled chloroform, brominated and total THMs increased after swimming by 10.9, 2.6 and 13.4, μg/m3, respectively. Creatinine-adjusted urinary TCAA increased by 3.1 μmol/mol. Micronuclei in lymphocytes and reticulocytes, urine mutagenicity and serum CC16 levels remained unchanged after swimming. Spearman correlation coefficients showed no association between DBP exposure and micronuclei in lymphocytes, urine mutagenicity and CC16. Moderate associations were observed for micronuclei in reticulocytes and DBP exposure. The unchanged levels of the short-term effect biomarkers after swimming and null associations with personal estimates of exposure to DBPs suggest no measurable effect on genotoxicity in lymphocytes, urine mutagenicity and lung epithelium permeability at the observed exposure levels. The moderate associations with micronuclei in reticulocytes require cautious interpretation given the reduced sample size. • We evaluated swimmers' exposure to disinfection by-products in exhaled air and urine. • We measured short-term effects on genotoxicity and lung damage biomarkers. • Chloroform and brominated THMs levels in exhaled breath increased after swimming. • Most of the effect biomarkers did not change after swimming. • Associations were found for micronuclei in reticulocytes but sample size was small. [ABSTRACT FROM AUTHOR]

Characterization of groundwater-surface water interactions remains challenging,especially in anthropogenically affected and geologically complex river systems. In thisstudy, groundwater inflow into the Ammer River was quantified by optimizingexfiltration rates in an implicit numerical model (FINIFLUX) to measured data ofseveral environmental tracers (e.g., sulfate (SO42−), radon (222Rn)) and organicconservative pollutants like carbamazepine and sulfamethoxazole emitted via awastewater treatment plant (WWTP). Modelling results of the selected tracers werecompared. The investigated Ammer River is strongly karstified and anthropogenically modified (millcanals, weirs, numerous artificial inputs) but representative for many small river systems inEurope. 222Rn activities in the river ranged from 500 to 3300 Bq m−3 and SO42−concentrations from 224 to 291 mg L−1. Concentrations of carbamazepine (90-130 ng L−1)and sulfamethoxazole (55-100 ng L−1) in the river water result from effluents of aWWTP. All tracers indicate major local groundwater inflows over the 6 km riverreach. Additional high peaks mainly observed in 222Rn activities indicate inputsalong geological fault lines, whereby increasing concentrations of carbamazepineand sulfamethoxazole may be attributed to inputs of groundwater contaminated byinfiltration of wastewater from a nearby WWTP. 222Rn-based calculations showed thebest optimization performance (R2=0.90) and result in a reasonable cumulativegroundwater inflow of 0.274 m3 s−1 (28.5% of total discharge) for the investigated reach.Poor optimizations for the other tracers may be due to the diurnal pattern of ionconcentrations induced by the WWTP and measurement uncertainties and the smallconcentration differences between river water and groundwater for carbamazepine andsulfamethoxazole. In our case study, 222Rn seems to be the most suitable environmental tracer despiteuncertainties in degassing and determination of the groundwater endmember concentration.However, only a multi tracer approach can account for the complexity of the investigatedriver system and may thus be indispensable for future investigations aiming to understandgroundwater-surface water interactions. [ABSTRACT FROM AUTHOR]

Anthropogenic organic micropollutants enter river systems mainly via wastewater treatment plants (WWTP). Characterization of turnover processes and fate of these compounds including temporal and spatial resolution at the same time remains challenging. Still, published results rely frequently on grab samples that do not account adequately for advection, dispersion and transformation along the studied reach. This study aims to compare degradation rates calculated from a Lagrangian Sampling concept in two different sequential reaches with calculations from arbitrary grab samples.Field investigations took place at two sequential reaches at the Ammer River close to Tübingen in the southwest of Germany that differ in (hydro-) morphology, slope and amount of groundwater inflow. Time-series measurements of organic chemical compounds (target screening), accompanied by electrical conductivity (EC), and conservative ions were conducted over a period of 24 hours. A lumped parameter model approach accounting for advection and dispersion was applied to the time-series measurements to calculate degradation rate constants affecting water parcels entering and leaving the same reach. In an alternative approach, degradation rate constants were calculated from arbitrary grab samples of the time series, representative for samples not properly considering travel time of water in the river. The influence of dilution caused by tributary and groundwater inflow was included for the overall attenuation rate in both approaches. The Lagrangian sampling approach integrates temporal dynamics such as the changed solar radiation or input of the WWTP into the river throughout the whole day and thus leads to representative degradation rates and characterization of turnover processes. In contrast, results from arbitrary grab samples may be misleading and indicating unrealistic processes and rates.The different results of the tested approaches show the relevance of identifying and including temporal and spatial aspects of river systems for characterization of the fate of organic micropollutants. They highlight the need to consider hydrological processes in the river for future field-based attenuation investigations. [ABSTRACT FROM AUTHOR]