Over the past decade, the application of liquid chromatography-high resolution mass spectroscopy (LC-HRMS) has been growing extensively due to its ability to analyze a wide range of suspected and ...unknown compounds in environmental samples. However, various criteria, such as mass accuracy and isotopic pattern of the precursor ion, MS/MS spectra evaluation, and retention time plausibility, should be met to reach a certain identification confidence. In this context, a comprehensive workflow based on computational tools was developed to understand the retention time behavior of a large number of compounds belonging to emerging contaminants. Two extensive data sets were built for two chromatographic systems, one for positive and one for negative electrospray ionization mode, containing information for the retention time of 528 and 298 compounds, respectively, to expand the applicability domain of the developed models. Then, the data sets were split into training and test set, employing k-nearest neighborhood clustering, to build and validate the models’ internal and external prediction ability. The best subset of molecular descriptors was selected using genetic algorithms. Multiple linear regression, artificial neural networks, and support vector machines were used to correlate the selected descriptors with the experimental retention times. Several validation techniques were used, including Golbraikh–Tropsha acceptable model criteria, Euclidean based applicability domain, modified correlation coefficient (r m 2), and concordance correlation coefficient values, to measure the accuracy and precision of the models. The best linear and nonlinear models for each data set were derived and used to predict the retention time of suspect compounds of a wide-scope survey, as the evaluation data set. For the efficient outlier detection and interpretation of the origin of the prediction error, a novel procedure and tool was developed and applied, enabling us to identify if the suspect compound was in the applicability domain or not.
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•Electrokinetic soil remediation was assessed by high-resolution mass spectrometry.•Oxygen-rich molecules were transported to the anode by electromigration.•Large hydrogen-rich ...molecules were carried to the cathode by electroosmotic flow.•A highly automated suspect screening method for >3000 PFASs was applied.•The overlooked contaminant perfluoroheptanesulfonic acid was tentatively identified.
Contamination of soils with organic pollutants is an increasing global problem, so novel soil remediation techniques are urgently needed. One such technique is electrokinetic remediation, in which an electric field is applied over the soil to extract contaminants. Previous evaluations of the technique have been limited to a few specific compounds. In this study, we integrated the latest advances in high-resolution mass spectrometry (HRMS) to identify molecular fingerprints, and used the results to improve the mechanistic understanding necessary for successful remediation. A laboratory-scale 0.38 mA cm−2 electrodialytic treatment was applied for 21 days to a contaminated soil from a firefighter training facility in Sweden. Non-target analysis allowed generic evaluation of changes in the soil organic fraction by tentatively determining the elemental composition of compounds present. The results showed that smaller oxygen-rich molecules were significantly transported to the anode by electromigration, while larger hydrogen-saturated molecules were transported to the cathode by electroosmotic flow. Wide suspect screening with >3000 per- and polyfluoroalkyl substances (PFASs) tentatively identified seven new PFASs in the test soil, including perfluoroheptanesulfonic acid (PFHpS), and PFASs with butoxy, ethoxy, ethanol, and ethylcyclohexanesulfonate functional groups.
A bench-scale column experiment was performed to study the removal of 31 selected organic micropollutants (MPs) and phosphorus by lignite, xyloid lignite (Xylit), granular activated carbon (GAC), ...Polonite® and sand over a period of 12 weeks. In total 29 out of the 31 MPs showed removal efficiency >90% by GAC with an average removal of 97 ± 6%. Xylit and lignite were less efficient with an average removal of 80 ± 28% and 68 ± 29%, respectively. The removal efficiency was found to be impacted by the characterization of the sorbents and physicochemical properties of the compounds, as well as the interaction between the sorbents and compounds. For instance, Xylit and lignite performed well for relatively hydrophobic (log octanol/water partition coefficient (Kow) ≥3) MPs, while the removal efficiency of moderately hydrophilic, highly hydrophilic and negatively charged MPs were lower. The organic sorbents were found to have more functional groups at their surfaces, which might explain the higher adsorption of MPs to these sorbents. The removal of several MPs improved after four weeks in sand, Xylit, GAC and lignite which may be related to increased biological activity and biofilm development. GAC and sand had limited ability to remove phosphorus (12 ± 27% and 14 ± 2%, respectively), while the calcium-silicate material Polonite® precipitated phosphorus efficiently and increased the total phosphorus removal from 12% to 96% after the GAC filter.
•Physicochemical properties of the compound are important for the adsorption process.•The characteristics of the sorbents influence the removal rate.•The removal mechanisms are affected by the interaction between sorbent and compound.•Simultaneous removal of MPs and phosphorus occurs by combining GAC and Polonite®.
•BFRs and UV-F levels were comparable to those reported in other regions of the world.•The contamination was greater in Colombian sites.•Contribution of BFRs was higher than that of UV-F for almost ...all sediments.•Deca-BDE was the formulation used in Colombia, whereas Penta-BDE was also applied in Chile.•DBDPE was detected only in Chilean samples.
In the present study the occurrence of emerging hydrophobic organic pollutants in sediment samples from South America (Chile and Colombia) was investigated for the first time. Nineteen Chilean and thirteen Colombian sediment samples were analyzed in order to determine their content of brominated flame retardants (BFRs) (including PBDEs and emerging BFRs) as well as UV filters (UV-F). Samples were collected from neighboring aquatic ecosystems highly urbanized and industrialized in Colombia (Magdalena River area) and Chile (Biobio region). Different analytical procedures were applied depending on the selected analytes, based on chromatographic and mass spectrometric methodologies (GC–MS and LC–MS–MS). In general, concentration levels of both BFRs (up to 2.43 and 143ngg−1 dw of PBDEs in Chile and Colombia, respectively) and UV-F (nd–2.96 and nd–54.4ngg−1 dw in Chile and Colombia, respectively) were in the low range of published data, and the contribution of BFRs was higher than that of UV-F for almost all the sampled sediments.
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•Target GC-MS analysis partially explained the AOX present in chlor(am)inated water.•FT-ICR MS showed only 19 formulae common to all drinking water treatment plants.•Diversity of ...halogenated DBPs in chloraminated water was comparable to chlorinated water.•Only 8 formulae were detected with both negative ionization FT-ICR MS and LC-Orbitrap MS.•86 DBPs were tentatively identified with LC-Orbitrap MS. Workflow used is provided.
To date, there is no analytical approach available that allows the full identification and characterization of highly complex disinfection by-product (DBP) mixtures. This study aimed at investigating the chemodiversity of drinking water halogenated DBPs using diverse analytical tools: measurement of adsorbable organic halogen (AOX) and mass spectrometry (MS)-based target and non-target analytical workflows. Water was sampled before and after chemical disinfection (chlorine or chloramine) at four drinking water treatment plants in Sweden. The target analysis had the highest sensitivity, although it could only partially explain the AOX formed in the disinfected waters. Non-target Fourier transform ion cyclotron resonance (FT-ICR) MS analysis indicated that only up to 19 Cl and/or Br-CHO formulae were common to all disinfected waters. Unexpectedly, a high diversity of halogenated DBPs (presumed halogenated polyphenolic and highly unsaturated compounds) was found in chloraminated surface water, comparable to that found in chlorinated surface water. Overall, up to 86 DBPs (including isobaric species) were tentatively identified using liquid chromatography (LC)-Orbitrap MS. Although further work is needed to confirm their identity and assess their relevance in terms of toxicity, they can be used to design suspect lists to improve the characterization of disinfected water halogenated mixtures.
•First fully automated on-line SPE–LC–MS/MS determination of UV filters.•Method suitable to determine UV F of a wide range of physicochemical properties.•Sensitivity achieved allowing trace UV F ...determination in several water matrices.•First determination of UV filters residues in groundwater.
This paper describes the development and validation of the first fully automated method, based on on-line solid phase extraction–liquid chromatography–tandem mass spectrometry (on line-SPE–LC–MS/MS), for the determination of UV filters (UV F) and transformation products, with a wide range of physicochemical properties. The developed method was validated and applied to the analysis of the selected compounds in river water (RW), groundwater (GW), influent and effluent wastewater (IWW and EWW). Comparing with the off-line methodologies published so far the presented method provides several advantages including a shorter extraction time, lower sample volume and minimum manipulation. Low limits of detection were achieved for all the studied matrices, <3ng/L (GW), <3.5ng/L (RW), <4ng/L (EWW) and <10ng/L (IWW), allowing a reliable and accurate quantification of the analytes at trace level. SPE optimization and critical aspects associated with the trace level determination of the target compounds (e.g. matrix effects) have been also considered and discussed. The method was successfully applied to the analysis of the UV F in five real water samples of each considered matrix, being the first time that these compounds were determined in GW.
Waste water treatment facilities are a major sources of organic micropollutants (MPs) in surface water. In this study, surface water samples were collected from seven sites along a river system in ...Uppsala, Sweden, during four seasons and evaluated based on the occurrence of MPs in the samples and bioactivity using in vitro bioassays. The sampling sites were differentially impacted by on-site sewage treatment facilities (OSSFs), small scale, and large scale waste water treatment plants (WWTPs). The bioassays used included activation of aryl hydrocarbon receptor (AhR), estrogen receptor (ER), nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB), nuclear factor erythroid 2-related factor 2 (Nrf2), and androgen receptor (AR). Occurrence of 80 MPs, were analyzed using liquid chromatography coupled to tandem mass spectrometry. Most water samples induced AhR activity, and all sampling sites showed a similar profile regarding this activity. With the exception of one water sample, we did not detect any NFkB, Nrf2 or AR activity of the water samples. The exception was a sample impacted by OSSFs, which showed an activity in multiple bioassays, but the activity could not be explained by the occurrence of target MPs. The occurrence of MPs showed a spatial trend, with the highest number and amount of MPs detected in the samples collected downstream of the WWTPs, where up to 47 MPs were detected in one single sample. A seasonal variation was observed with highest levels of MPs and highest AhR activities in samples collected in June and September 2015. However, neither the seasonal activity nor the on-site activity could be explained by the measured MPs, suggesting unknown contributory agents in the water.
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•First report of eight compounds from personal care products (PCPs) in cord blood.•The most frequently detected and predominant paraben was methylparaben.•Seven compounds are reported ...in cord blood for the first time (level 1).•Ultraviolet filters (UVFs) and parabens (PBs) presence demonstrates mother-fetus transfer.•PCP-related compounds occurrence in cord blood suppose an exposure to the fetus.
Prenatal exposure to certain organic chemicals like pesticides and phenols has been lifelong associated with birth outcomes and health disorders. Many personal care product (PCP) ingredients have similar properties or structures to those chemicals. Previous studies have documented the occurrence of UV filters (UVFs) and paraben preservatives (PBs) in the placenta, but observational studies concerning PCPs chemicals and foetal exposure are particularly scarce. Thus, this work aimed to assess the presence of a wide range of PCPs chemicals using target and suspect screening in the umbilical cord blood of new born babies to evaluate their potential transfer to the fetus. To do so, we analysed 69 umbilical cord blood plasma samples from a mother–child cohort from Barcelona (Spain). We quantified 8 benzophenone-type UVFs and their metabolites, and 4 PBs using validated analytical methodologies based on target screening using liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Then, we screened for additional 3246 substances using high-resolution mass spectrometry (HRMS) and advanced suspect analysis strategies. Six UVFs and three parabens were detected in the plasma with frequencies between 1.4% and 17.4% and concentrations up to 53.3 ng/mL (benzophenone-2). Thirteen additional chemicals were tentatively identified in the suspect screening, and ten were further confirmed with the corresponding standards. Among them, we found the organic solvent N-methyl-2-pyrrolidone, the chelating agent 8-hydroxyquinoline, and the antioxidant 2,2′-methylenebis(4-methyl-6-tert-butylphenol), which have been demonstrated to display reproductive toxicity. UVFs and PBs presence in the umbilical cord blood demonstrates mother-fetus transfer through the placental barrier and prenatal exposure to these PCPs chemicals, which may lead to adverse effects in the early stages of fetal development. Considering the small cohort used in this study, the reported results should be interpreted as a preliminary reference for the background umbilical cord transfer levels of the target PCPs chemicals. Further research is needed to determine the long-term consequences of prenatal exposure to PCPs chemicals.
Photodecomposition might be regarded as one of the most important abiotic factors affecting the fate of UV absorbing compounds in the environment and photocatalysis has been suggested as an effective ...method to degrade organic pollutants. However, UV filters transformation appears to be a complex process, barely addressed to date. The white rot fungus Trametes versicolor is considered as a promising alternative to conventional aerobic bacterial degradation, as it is able to metabolise a wide range of xenobiotics. This study focused on both degradation processes of two widely used UV filters, benzophenone-3 (BP3) and benzophenone-1 (BP1). Fungal treatment resulted in the degradation of more than 99% for both sunscreens in less than 24h, whereas photodegradation was very inefficient, especially for BP3, which remained unaltered upon 24h of simulated sunlight irradiation. Analysis of metabolic compounds generated showed BP1 as a minor by-product of BP3 degradation by T. versicolor while the main intermediate metabolites were glycoconjugate derivatives. BP1 and BP3 showed a weak, but significant estrogenic activity (EC50 values of 0.058mg/L and 12.5mg/L, respectively) when tested by recombinant yeast assay (RYA), being BP1 200-folds more estrogenic than BP3. Estrogenic activity was eliminated during T. versicolor degradation of both compounds, showing that none of the resulting metabolites possessed significant estrogenic activity at the concentrations produced. These results demonstrate the suitability of this method to degrade both sunscreen agents and to eliminate estrogenic activity.
► Fungus T. versicolor is able to degrade totally BP3 and BP1 in few hours in a fluidised bed bioreactor. ► BP3 is not degraded under simulated sunlight. ► Glycoconjugates have been identified as the main intermediate metabolites. ► Decrease in endocrine activity was found in both photodegradation and biodegradation.
► New multi-residue LC–MS/MS method for the analysis of UV filters in fish. ► In-cell PLE purification and further SPE clean-up yielded clean fish extracts. ► Method suitable to determine UV F of a ...wide range of physicochemical properties. ► Low limits of detection achieved allowing for UV F bioaccumulation studies in fish. ► First data on the occurrence of UV filters residues in biota from Iberian rivers.
So far, the very few studies addressing the occurrence of UV filters (UV F) in biota showed important limitations in the analysis of the so complex biological matrices. In order to improve the knowledge on the bioaccumulation of UV F by fish, a simple and highly sensitive method was successfully developed and validated for the simultaneous determination of eight extensively used UV F and transformation products with a wide range of physicochemical properties. The present study demonstrated that liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) using a QqLIT mass analyser was applicable to the simultaneous analysis of UV F in fish. Pressurized liquid extraction (PLE) was chosen for the sample pretreatment due to the good extraction efficiency provided. An additional SPE clean-up step was added in order to minimize matrix effects and to improve the sensitivity. The method allowed recovery efficiencies in the range 70–112% for most compounds at the three spike levels. The low limits of detection (MLOD) achieved (0.1–6.0ng/g dw) allowed the reliable quantification of UV F residues in fish samples. The developed methodology was applied to assess the occurrence of UV F in different fish species from the Guadalquivir river basin (Spain). Results confirmed the bioaccumulation of benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC) and octocrylene (OC) in the fish samples. The maximum concentration of 240ng/g dw corresponded to EHMC, which was also the most ubiquitous compound. The reported concentrations constitute the first occurrence data of UV F residues in fish from Iberian rivers.
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