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Plastic pollution and associated plasticizers are a global threat affecting aquatic environments. Phthalates are among the most used plasticizers that can impact on fauna due to their endocrine-disrupting properties. The aim of this study was to investigate the use of eggs of Audouin's gull (Larus audouinii) and yellow-legged gull (Larus michahellis) as biomonitors of phthalate exposure. Sixteen phthalates were studied and the extraction and purification steps were optimized using various sorbents and clean-up processes to efficiently recover these contaminants in gull eggs. Analysis was performed using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) using multiple reaction monitoring to obtain high selectivity and sensitivity. Quality control parameters and a comprehensive analysis of blank contribution are provided. The best performance was obtained with Oasis PRiME HLB cartridges with recoveries from 61 to 138% for most of the compounds. Pooled gull-egg samples from seven breeding colonies collected over the period 2016-2021 within the Iberian Peninsula revealed the presence of dibutoxyethyl phthalate (DBEP), hexyl 2-ethylhexyl phthalate (HEHP), dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP) at mean concentrations ranging from 2.27 to 1330 ng/g ww in Audouin's gull and from 2.74 to 487 ng/g ww in yellow-legged gull (DBP not detected). The absence of other phthalates is likely attributable to their metabolism and excretion by female adults. Overall, this study provides an accurate method to analyse phthalates in gull eggs and supports their use as bioindicators of phthalate contamination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

In recent years, instrumental improvements have enabled the spread of mass spectrometry-based lipidomics platforms in biomedical research. In mass spectrometry, the reliability of generated data varies for each compound, contingent on, among other factors, the availability of labeled internal standards. It is challenging to evaluate the data for lipids without specific labeled internal standards, especially when dozens to hundreds of lipids are measured simultaneously. Thus, evaluation of the performance of these platforms at the individual lipid level in interlaboratory studies is generally not feasible in a time-effective manner. Herein, using a focused subset of sphingolipids, we present an in-house validation methodology for individual lipid reliability assessment, tailored to the statistical analysis to be applied. Moreover, this approach enables the evaluation of various methodological aspects, including discerning coelutions sharing identical selected reaction monitoring transitions, pinpointing optimal labeled internal standards and their concentrations, and evaluating different extraction techniques. While the full validation according to analytical guidelines for all lipids included in a lipidomics method is currently not possible, this process shows areas to focus on for subsequent method development iterations as well as the robustness of data generated across diverse methodologies., (© 2024. The Author(s).)

New data-independent acquisition (DIA) modes coupled to chromatographic separations are opening new perspectives in the processing of massive mass spectrometric (MS) data using chemometric methods. In this work, the application of the regions of interest multivariate curve resolution (ROIMCR) method is shown for the simultaneous analysis of MS1 and MS2 DIA raw data obtained by liquid chromatography coupled to quadrupole-time-of-flight MS analysis. The ROIMCR method proposed in this work relies on the intrinsic bilinear structure of the MS1 and MS2 experimental data which allows us for the fast direct resolution of the elution and spectral profiles of all sample constituents giving measurable MS signals, without needing any further data pretreatment such as peak matching, alignment, or modeling. Compound annotation and identification can be achieved directly by the comparison of the ROIMCR-resolved MS1 and MS2 spectra with those from standards or from mass spectral libraries. ROIMCR elution profiles of the resolved components can be used to build calibration curves for the prediction of their concentrations in complex unknown samples. The application of the proposed procedure is shown for the analysis of mixtures of per- and polyfluoroalkyl substances in standard mixtures, spiked hen eggs, and gull egg samples, where these compounds tend to accumulate.

Monoaminergic neurotransmitters are the main components that regulate of a lot of processes in the vertebrate brain. There is growing interest to monitor the changes produced in these neurochemicals due to the large number of exogenous agents, such as pharmaceuticals and drugs of abuse, targeting and affecting this system. Adult zebrafish (Danio rerio) shares the common neurotransmitter pathways and nervous system organization with mammals. Therefore, a method based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been developed for the first time to study the profile of ten monoaminergic neurochemicals in the anterior, middle and posterior brain regions of adult zebrafish. Moreover, the applied LC-MS/MS method has been studied in terms of quality such as linearity, sensitivity and intra- and inter-day precision. The analytical method based in LC-MS/MS has become a new source in neurotoxicology using adult zebrafish as research model. Significant differences on the levels of these neurotransmitters have been found between the different brain regions. CAPSULE: The profile of ten monoaminergic neurochemicals in the main three brain areas of adult zebrafish has been reported for the first time in this manuscript., Competing Interests: Declaration of competing interest Please check the following as appropriate:, (Copyright © 2020 Elsevier B.V. All rights reserved.)

It has been reported that antidepressant, anxiolytic and antihypertensive drugs alter the behavior and reproduction of the microcrustacean Daphnia magna at very low concentrations. However, there is little evidence for how these drugs act on their neurotransmitter targets. A method based on hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry has been developed and applied for the first time using D. magna extracts and validated by studying the changes in the levels of a suite of neurotransmitters caused by five different neuroactive pharmaceuticals (fluoxetine, venlafaxine, carbamazepine, propranolol, and diazepam) dosed at 100 ng/L. Sample extraction and chromatographic and detection conditions were optimized for accurate detection of the selected neurotransmitters in whole D. magna organisms. The method allowed the simultaneous quantification of eight neurotransmitters belonging to six neuroendocrine systems: the dopaminergic, adrenergic, GABAergic, serotoninergic, histaminergic, and cholinergic systems. Neurotransmitters were eluted with a ZIC-HILIC column and quantified by tandem mass spectrometry in positive electrospray ionization mode performed in multiple reaction monitoring mode. All method validation assays (i.e., quality controls for linearity, sensitivity, accuracy, precision, stability, recovery, matrix effect, and carryover) were compliant with the standard requirements for similar analysis. Exposure to fluoxetine enhanced serotonin concentrations, whereas exposure to diazepam decreased the levels of dopamine, and exposure to propranolol increased the levels of norepinephrine. Exposure to both propranolol and diazepam decreased the levels of histamine. The results show the usefulness of this approach for environmental neurotoxicity studies. Graphical abstract.

Elderly people represent about the 15% of the total world population and often include a polymedicated age group with an average consumption of 5-10 pills per day. The main pharmaceuticals consumed are antianalgesics, antidiabetics, anti-parkinson compounds, anti-convulsants, drugs to treat constipation and drugs to treat cancer. In this study, we have developed a multiresidue method for the analysis of 44 selected pharmaceuticals prioritized according to the foremost consumption by the elderly in effluents from senior residences. Given the complexity of these waters, method optimization included the selection of the extraction cartridge, pH and volume, and the optimization of the liquid chromatography-tandem mass spectrometry conditions to minimize matrix effects and obtain high yields. Good method performance was obtained, with recoveries between 27 and 116% and high sensitivity. The method was tested in a preliminar study to determine pharmaceuticals released in situ from the untreated effluents of the senior residences. High concentrations were detected, with levels between 0.20 and 2891 μg L -1 attributed to the high consumption of drugs in the studied residences, which gather around 100 residents. The most detected pharmaceuticals were aspirin, macrogol, levofloxacin, cyclophosphamide, diclofenac, ibuprofen, paracetamol, carbamazepine, levetiracetam, pregabalin, quetiapine, chlormetiazole, trazodone, caffeine, 2,4-dichlorobenzyl alcohol and amylmetacresol. This study describes the analytical conditions to determine the outmost consumed pharmaceuticals in wastewaters released from senior residences., (Copyright © 2019. Published by Elsevier B.V.)

We present capillary electrophoresis-mass spectrometry (CE-MS) in combination with advanced chemometric tools for the analysis of bioactive compounds in food, in particular for the identification of antihypertensive peptides in a nutraceutical derived from a bovine milk protein hydrolysate. Different extracts of the nutraceutical were analyzed by CE-MS, and the electropherograms were processed using a novel data analysis workflow that included regions of interest (ROIs) compression and multivariate curve resolution alternating least squares (MCR-ALS). MCR-ALS permitted the description of the nutraceutical extract as ten characteristic components with their electrophoretic profiles and mass spectra. Twenty-two compounds were tentatively identified as antihypertensive bovine casein fragments through a mass search in a database of bioactive peptides. The identity of 17 antihypertensive peptides was reliably confirmed by capillary electrophoresis-tandem mass spectrometry. The proposed analytical approach demonstrated the potential to obtain a characteristic and activity-related fingerprint for quality control and authentication of the antihypertensive nutraceutical., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The evaluation of wastewater treatment capabilities in terms of removal of water pollutants is crucial when assessing water mitigation issues. Not only the monitoring of target pollutants becomes a critical point, but also the transformation products (TPs) generated. Since these TPs are very often unknown compounds, their study in both wastewater and natural environment is currently recognized as a tedious task and challenging research field. In this study, a novel automated suspect screening methodology was developed for a comprehensive assessment of the TPs generated from nine antibiotics during microalgae water treatment. Three macrolides (azithromycin, erythromycin, clarithromycin), three fluoroquinolones (ofloxacin, ciprofloxacin, norfloxacin) and three additional antibiotics (trimethoprim, pipemidic acid, sulfapyridine) were selected as target pollutants. The analysis of samples was carried out by direct injection in an on-line turbulent flow liquid chromatography-high resolution mass spectrometry (TFC-LC-LTQ-Orbitrap-MS/MS) system, followed by automatic data processing for compound identification. The screening methodology allowed the identification of 40 tentative TPs from a list of software predicted intermediates created automatically. Once known and unknown TPs were identified, degradation pathways were suggested considering the different mechanisms involved on their formation (biotic and abiotic). Results reveal microalgae ability for macrolide biotransformation, but not for other antibiotics such as for fluoroquinolones. Finally, the intermediates detected were included into an in-house library and applied to the identification of tentative TPs in real toilet wastewater treated in a microalgae based photobioreactor (PBR). The overall approach allowed a comprehensive overview of the performance of microalgae water treatment in a fast and reliable manner: it represents a useful tool for the rapid screening of wide range of compounds, reducing time invested in data analysis and providing reliable structural identification., (Copyright © 2018 Elsevier B.V. All rights reserved.)

There is a growing interest in biological models to investigate the effect of neurotransmitter dysregulation on the structure and function of the central nervous system (CNS) at different stages of development. Zebrafish, a vertebrate model increasingly used in neurobiology and neurotoxicology, shares the common neurotransmitter systems with mammals, including glutamate, GABA, glycine, dopamine, norepinephrine, epinephrine, serotonin, acetylcholine, and histamine. In this study, we have evaluated the performance of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the multiresidue determination of neurotransmitters and related metabolites. In a first step, ionization conditions were tested in positive electrospray mode and optimum fragmentation patterns were determined to optimize two selected reaction monitoring (SRM) transitions. Chromatographic conditions were optimized considering the chemical structure and chromatographic behavior of the analyzed compounds. The best performance was obtained with a Synergy Polar-RP column, which allowed the separation of the 38 compounds in 30 min. In addition, the performance of LC-MS/MS was studied in terms of linearity, sensitivity, intra- and inter-day precision, and overall robustness. The developed analytical method was able to quantify 27 of these neurochemicals in zebrafish chemical models for mild (P1), moderate (P2), and severe (P3) acute organophosphorus poisoning (OPP). The results show a general depression of synaptic-related neurochemicals, including the excitatory and inhibitory amino acids, as well as altered phospholipid metabolism, with specific neurochemical profiles associated to the different grades of severity. These results confirmed that the developed analytical method is a new tool for neurotoxicology research using the zebrafish model.

A liquid chromatography quadruple time-of-flight mass spectrometry (LC-QqTOF-MS/MS) method was developed for simultaneous quantitative analysis of ibuprofen (IBU), 1- and 2-hydroxyibuprofen (1-OH IBU and 2-OH IBU), and carboxyibuprofen (CBX IBU) while preserving the ability of the instrument to get precursor and product ion mass spectra of non-target compounds. The trigger was the precursor ions reaching 100 cps intensity. Sample preparation was carried out by ultrasound solid-liquid extraction with methanol as extraction solvent at pH < 2 followed by solid-phase extraction (SPE) clean-up using STRATA-X cartridges and methanol as an eluent. Linearity was obtained in the range 50-10,000 ng mL -1 for IBU, each OH IBU and CBX IBU (r ≥ 0.99). The proposed method was satisfactorily validated showing absolute recoveries of > 70% for all target analytes at low and high concentration levels. The lowest limit of quantification was < 50 ng g -1 in plant. This method was applied to investigate IBP behavior in cowpea (Vigna unguiculata (L.) Walp) treated at high IBU concentrations and its presence in vegetables irrigated with treated water. Up to 46 metabolites, mostly hydroxylated metabolites and conjugates with hexosides and amino acids, were identified. The most abundant metabolites were also identified in an eggplant sample. Graphical Abstract ᅟ Ibuprofen metabolite identification.

In this work, two knowledge integration strategies based on multivariate curve resolution alternating least squares (MCR-ALS) were used for the simultaneous analysis of data from two metabolomic platforms. The benefits and the suitability of these integration strategies were demonstrated in a comparative study of the metabolite profiles from yeast (Saccharomyces cerevisiae) samples grown in non-fermentable (acetate) and fermentable (glucose) carbon source. Untargeted metabolomics data acquired by capillary electrophoresis-mass spectrometry (CE-MS) and liquid chromatography-mass spectrometry (LC-MS) were jointly analysed. On the one hand, features obtained by independent MCR-ALS analysis of each dataset were joined to obtain a biological interpretation based on the combined metabolic network visualization. On the other hand, taking advantage of the common spectral mode, a low-level data fusion strategy was proposed merging CE-MS and LC-MS data before the MCR-ALS analysis to extract the most relevant features for further biological interpretation. Then, results obtained by the two presented methods were compared. Overall, the study highlights the ability of MCR-ALS to be used in any of both knowledge integration strategies for untargeted metabolomics. Furthermore, enhanced metabolite identification and differential carbon source response detection were achieved when considering a combination of LC-MS and CE-MS based platforms., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The presence of antibiotics in seafood for human consumption may pose a risk for consumers. A methodology for the analysis of antibiotics in seafood based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction, followed by detection and quantification using liquid chromatography coupled to mass spectrometry was developed. The analytical method was evaluated for the determination of 23 antibiotics (including parent compounds and some metabolites) in fish, mussels and clams. Recoveries ranged between 30% and 70% for most of the compounds and method detection and quantification limits (MDLs and MQLs) were between 0.01 and 0.31 ng/g dry weigh (dw) and 0.02-1.03 ng/g (dw) respectively. Real seafood samples were analysed using this method. Nine antibiotics were found at levels above MDLs; however none of them exceed the maximum residue limits (MRL) established by the authorities. Tetracycline was the most ubiquitous compound, presenting also the highest concentration: 5.63 ng/g (dw) in fish from Netherlands. In addition, an alternative technique based on microbial growth inhibition was explored as semiquantitative detection method of antibiotics in seafood. This methodology could be applied as a fast screening technique for the detection of macrolides and β-lactams in seafood but further research is needed for other antibiotics families., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A new methodology based on on-line solid-phase extraction (SPE) ultra-high-performance-liquid chromatography coupled to a triple quadrupole mass spectrometer (UHPLC-MS-MS) for the determination of 15 individual anthropogenic N-nitrosodimethylamine (NDMA) precursors was developed. On-line SPE was performed by passing 2mL of the water sample through a Hypersil GOLD aQ column and chromatographic separation was done using a Kinetex Biphenyl column using methanol and 0.1% formic acid aqueous solution as a mobile phase. For unequivocal identification and confirmation, two selected reaction monitoring (SRM) transitions were monitored per compound. Quantification was performed by internal standard approach and matrix match calibration. The main advantages of the developed method are high sensitivity (limits of detection in the sub ng/L range), selectivity due to the use of tandem mass spectrometry, precision and minimum sample manipulation as well as fast analytical response. Process efficiency and recovery were also evaluated for all the target compounds. As part of the validation procedure, the method was applied in a sampling campaign for the analysis of influent and secondary effluent of a wastewater treatment plant (WWTP) in Girona, Spain. Additionally, the effluent from a nanofiltration (NF) membrane system used for water recycling was monitored. The percentage of NDMA formation explained by the measured precursors was also quantified., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Microcystins, anatoxins and okadaic acid are toxins produced by freshwater cyanobacteria and marine dinoflagellates. These toxins have been the responsible for the illness and death of biota and humans. To determine their presence in water during blooms, sensitive analytical methods are needed. In this study, we have developed a new liquid chromatography tandem mass spectrometry (LC-MS/MS) method for fast multiresidue determination of five toxins in suspended material and sediment samples. For each target compound, two selected reaction monitoring (SRM) transitions were optimised. Chromatographic conditions were optimised considering that the compounds analysed had different chemical structure and chromatographic behaviour. Using a Luna C18 column and specific SRM transitions, five phytotoxins were resolved. Method detection limits (MDL) for anatoxin-a, microcystins RR, LR and YR and okadaic acid were 7.1, 3.3, 81.7, 102.8 and 28.8 ng g(-1) dry weight in sediment, respectively. The developed analytical method was successfully applied to analyse the presence of toxins in suspended solids and sediment from Ebro River (NE Spain) and Ebro delta-associated lagoons. Anatoxin-a was detected downstream of the Riba-Roja reservoir with levels ranging from 20 to 1120 ng g(-1) dry weight of suspended solids. Okadaic acid was only detected in three samples collected in the Alfacs Bay (Ebro delta, Spain) affected by Dinophysis blooms in 2012.

A novel fully automated method based on dual column switching using turbulent flow chromatography followed by liquid chromatography coupled to tandem mass spectrometry (TFC-LC-MS/MS) was applied for the determination of endocrine disruptors (EDCs) and related compounds in sediment and sewage sludge samples. This method allows the unequivocal identification and quantification of the most relevant environmental EDCs such as natural and synthetic estrogens and their conjugates, antimicrobials, parabens, bisphenol A (BPA), alkylphenolic compounds, benzotriazoles, and organophosphorus flame retardants, minimizing time of analysis and alleviating matrix effects. Applying this technique, after the extraction of the target compounds by pressurized liquid extraction (PLE), sediment and sewage sludge extracts were directly injected to the chromatographic system and the analytes were concentrated into the clean-up loading column. Using six-port switching system, the analytes were transferred to the analytical column for subsequent detection by MS-MS (QqQ). In order to optimize this multiplexing system, a comparative study employing six types of TurboFlow™ columns, with different chemical modifications, was performed to achieve the maximum retention of analytes and best elimination of matrix components. Using the optimized protocol low limits of quantification (LOQs) were obtained ranging from 0.0083 to 1.6 ng/g for sediment samples and from 0.10 to 125 ng/g for sewage sludge samples (except for alkylphenol monoethoxylate). The method was used to evaluate the presence and fate of target EDCs in the Ebro River which is the most important river in Spain with intensive agricultural and industrial activities in the basin that contribute to deteriorating soil and water quality., (Copyright © 2014 Elsevier B.V. All rights reserved.)

This paper describes the development and application of a multi-residue chiral liquid chromatography coupled with tandem mass spectrometry method for simultaneous enantiomeric profiling of 18 chiral pharmaceuticals and their active metabolites (belonging to several therapeutic classes including analgesics, psychiatric drugs, antibiotics, cardiovascular drugs and β-agonists) in surface water and wastewater. To the authors' knowledge, this is the first time an enantiomeric method including such a high number of pharmaceuticals and their metabolites has been reported. Some of the pharmaceuticals have never been studied before in environmental matrices. Among them are timolol, betaxolol, carazolol and clenbuterol. A monitoring programme of the Guadalquivir River basin (South Spain), including 24 sampling sites and five wastewater treatment plants along the basin, revealed that enantiomeric composition of studied pharmaceuticals is dependent on compound and sampling site. Several compounds such as ibuprofen, atenolol, sotalol and metoprolol were frequently found as racemic mixtures. On the other hand, fluoxetine, propranolol and albuterol were found to be enriched with one enantiomer. Such an outcome might be of significant environmental relevance as two enantiomers of the same chiral compound might reveal different ecotoxicity. For example, propranolol was enriched with S(-)-enantiomer, which is known to be more toxic to Pimephales promelas than R(+)-propranolol. Fluoxetine was found to be enriched with S(+)-enantiomer, which is more toxic to P. promelas than R(-)-fluoxetine.

The present study describes a novel, fully automated method, based on column switching using EQuan™ columns for an integrated sample preconcentration and liquid chromatography coupled to tandem mass spectrometry (LC-LC-MS/MS). The method allows the unequivocal identification and quantification of the most relevant environmental endocrine disruptors compounds (EDCs) and compounds suspected to be EDCs, such as natural and synthetic estrogens and their conjugates, antimicrobials, parabens, bisphenol A, alkylphenolic compounds, benzotriazoles, and organophosphorus flame retardants, in surface river water and wastewater samples. Applying this technique, water samples were directly injected into the chromatographic system and the target compounds were concentrated into the loading column. Thereafter, the analytes were transferred into the analytical column for subsequent detection by MS-MS (QqQ). A comparative study employing three types of columns, with different chemical modifications, was performed in order to determine the optimal column that allowed maximum retention and subsequent elution of the analytes. Using this new optimized methodology a fast and easy online methodology for the analysis of EDCs in surface river water and wastewater with low limits of quantification (LOQ) was obtained. LOQs ranged from 0.008 to 1.54 ng/L for surface river water and from 0.178/0.364 to 12.5/25.0 ng/L (except for alkylphenol monoethoxylates) for effluent/influent waste water. Moreover, employing approximately 1h, a complete analysis was performed which was significant improvement in comparison to other methods reported previously. This method was used to track the presence and fate of target compounds in the Ebro River which is the most important river in Spain whose intensive agricultural and industrial activities concentrate mainly close to the main cities in the basin, deteriorating soil and water quality., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Cytostatic compounds used in the treatment of cancer have emerged as a new generation of water contaminants due to the continuous amounts administered to patients and to the fact that a variable proportion is excreted unchanged. In this study, we have evaluated the performance of liquid-chromatography-tandem mass spectrometry (LC-MS/MS) and high resolution mass spectrometry using an Orbitrap analyzer (LC-HRMS) for the multiresidue determination of multi-class cytostatic compounds. In a first step, ionization conditions were tested in positive electrospray mode and optimum fragmentation patterns were determined. For LC-MS/MS, two selected reaction monitoring (SRM) transitions were optimized and for LC-HRMS, the molecular ion with 5 ppm error and two product ions were defined. Following, the chromatographic conditions were optimized considering that compounds analyzed have a very different chemical structure and chromatographic behavior. The best performance was obtained with a Luna C18 column, which permitted the separation of the 26 compounds in 15 min. Finally, the performance of LC-MS/MS and LC-HRMS was compared in terms of linearity, sensitivity, intra and inter-day precision and overall robustness. While LC-MS/MS provided good identification capabilities due to selective SRM transitions, LC-Orbitrap proved to be 100 times more sensitive. This study provides a comprehensive overview on the MS conditions to determine the outmost used cytostatic compounds and provides a spectral library to be used for the identification of these compounds in water or biological matrices., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The present study describes the development, validation and a practical application of a fully automated analytical method based on pressurized liquid extraction (PLE) followed by solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) for the simultaneous determination of 22 sulfonamides, including five acetylated metabolites, in sewage sludge and soil samples. Both matrix matched calibration curves and standard calibration curves were built in order to evaluate the potential matrix effects during analysis, and different internal standards were used to compensate these effects during quantification. The recovery efficiencies were found to be 60-130% for the majority of the sulfonamides in both matrices and at two spike levels. The intra-day and inter-day precisions, expressed by the relative standard deviation (RSD), were below 23%. The method limits of detection (MLODs) achieved were in the range 0.03-2.23 ng g(-1) for sewage sludge and 0.01-4.19 ng g(-1) for soil samples. The methodology was applied to evaluate the occurrence of the target sulfonamides in several sewage sludge and soil samples taken in different wastewater treatment plants (WWTPs) and agricultural areas. Results confirmed the wide presence of sulfonamides in both matrices, being sulfathiazole and sulfamethazine the sulfonamides most frequently detected in sewage sludge and soil samples, respectively. Maximum concentrations corresponded to sulfamethazine in both cases (139.2 ng g(-1) and 8.53 ng g(-1) for sewage sludge and soils respectively). Levels were generally lower in soils. Three of the five acetylated metabolites were detected in sewage sludge and two of them in soils, at concentrations not higher than 9.81 ng g(-1)., (Copyright © 2012 Elsevier B.V. All rights reserved.)

A fast on-line analytical method based on turbulent flow chromatography (TFC) in combination with tandem mass spectrometry has been applied for the first time for the analysis of eighteen perfluoroalkyl substances (PFASs), in cord blood. A simple and rapid sample pre-treatment was optimised consisting on protein precipitation of 100 μL of sample with acetonitrile (1:1) followed by centrifugation during 10 min. The method was adapted to be sensitive enough and robust with minimum sample injection volume requirements (20 μL). The optimised methodology presented method limits of detection (MLOD) between 0.031 and 0.76 μg/L, detection capabilities (CCα) in the range between 0.005 and 0.99 μg/L and decision limits (CCβ) ranging from 0.006 to 1.16 μg/L. The recoveries in blank blood were calculated by spiking experiments with a mixture of 18 PFASs and established between 70 and 126% for most of compounds. Isotopic dilution was carried out for quantification of selected analytes. In-house validation of this new approach was carried out according to the requirements in the 2002/657/EC Decision. Finally the good applicability of this new approach was proved by the analysis of 60 cord blood samples from two different Mediterranean cities, Barcelona (Spain) and Heraklion (Greece). Ions perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) were found at highest concentration and the more frequently compounds were PFHxS, PFOS and perfluorooctanoic acid (PFOA). The newly developed method proved to be suitable for large-scale epidemiologic studies, and to the data on PFASs exposure during pregnancy., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The work describes the development and validation of an analytical method for simultaneous determination of 58 pharmaceuticals and 19 metabolites and transformation products in environmental waters. The method is fully automated and consists of a direct injection of a small volume (several mL) of water sample to an on-line system composed of TurboFlow™ chromatography for the extraction and clean-up followed by liquid chromatography-electrospray-tandem mass spectrometry (TFC-LC-ESI-MS/MS). The feasibility and limitations of the technique in the analysis of environmental and wastewaters is discussed. The main advantages include high throughput, minimum sample manipulation, low error introduction, high selectivity, sensibility and reliability. The method provided a tool for the determination of a high number of active metabolites and transformation products and was successfully applied in the analysis of samples from the river Ebro basin., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Perfluorinated compounds (PFCs) are ubiquitous contaminants of humans and animals worldwide. PFCs are bioaccumulated because of their affinity for proteins. It has been shown they could have a variety of toxicological effects and cause damage to human health, emphasizing the need for sensitive and robust analytical methods to assess their bioaccumulation in humans. In this paper we report the development and validation of an analytical method for analysis of PFCs in the non-invasive human matrices hair and urine. The method is based on rapid and simple sample pre-treatment followed by online turbulent flow liquid chromatography and tandem mass spectrometry (TFC-LC-MS-MS) for analysis of 21 PFCs. The method was validated for both matrices. Percentage recovery was between 60 and 105 for most compounds in both matrices. Limits of quantification ranged from 0.1 to 9 ng mL(-1) in urine and from 0.04 to 13.4 in hair. The good performance of the method was proved by investigating the presence of selected PFCs in 24 hair and 30 urine samples from different donors living in Barcelona (NE Spain). The results were indicative of bioaccumulation of these compounds in both types of sample. PFOS and PFOA were most frequently detected in hair and PFBA in urine.

This work describes the development, optimization and validation of an analytical method for the simultaneous detection and identification of 74 pharmaceutically active compounds (PhACs), from various therapeutic groups, in both environmental (ground and surface water) and wastewaters (WW). The method is based on the simultaneous extraction of all target compounds by solid phase extraction (SPE), using a hydrophilic-lipophilic balanced polymer followed by ultra high performance liquid chromatography (UHPLC) tandem mass spectrometry (MS/MS). Two selected reaction monitoring (SRM) transitions have been monitored per compound in order to fulfil the EC guidelines, as well as to ensure an accurate identification of target compounds in the samples. Quantification is performed by internal standard approach, applying 24 specific isotopically labeled compounds. The main advantages of the developed method, besides the selectivity and reliability of the results, is its high throughput. All compounds are extracted in a single step and the instrumental analysis lasts 5 min (NI mode)+8 min (PI mode), allowing fast throughput of samples. The limits of detection range from 0.01 to 50 ng L(-1), depending on the matrix, for most of the compounds. Finally, the method developed has been applied to the analysis of pharmaceuticals in the Ebro river basin (NE Spain)., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Perfluorinated compounds (PFCs) are widely used in everyday life and one of the main recipients of these compounds is waste water treatment plants (WWTPs). Due to the structure and physicochemical properties of PFCs, these compounds could be redistributed from influent water to sludge. This work reports a new validated protocol for the analysis of 13 perfluorinated acids, 4 perfluorosulfonates and the perfluorooctanesulfonamide. The present work has been focused to develop a sensitive and robust method for the analysis of 18 PFCs in sewage sludge, based on pressurized solvent extraction (PSE) followed by solid phase extraction (SPE) clean-up, analytes separation by liquid chromatography and analysis in a hybrid quadrupole-linear ion trap mass spectrometer (LC-QLiT-MS/MS) working in single reaction monitoring (SRM) mode. The final methodology was validated using a blank sewage sludge fortified at different concentration levels. The method limits of detection were ranging in general from 15 to 79 ng/kg. These values were comparable to the decision limit (CCα) and the detection capability (CCβ), which were 17-1134 ng/kg and 18-1347 ng/kg, respectively. The percentage of recovery was from 79 to 111% in the most cases at different spiked levels. Finally, the repeatability of the method was in the range 4% (PFOS and PFOA) to 25% (RSD %). In order to evaluate the applicability of the method, 5 sludge samples were analyzed. The results showed that the 18 PFCs were present in all samples. However, the concentrations for most of them were below the limits of quantification. The compound present at higher concentrations was perfluorooctanesulfonate (PFOS), which was in concentrations from 53.0 to 121.1 μg/kg. The other PFCs were at concentrations between 0.3 and 30.3 μg/kg., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The analytical suitabilities of three different liquid chromatography-tandem mass spectrometry (LC-MS/MS) systems, (1) triple quadrupole (QqQ), (2) conventional 3D ion trap (IT), and (3) quadrupole-linear IT (QqLIT), to determine trace levels of perfluorinated compounds (PFCs) in fish and shellfish were compared. Sample preparation was performed using alkaline extraction and solid-phase-extraction cleanup. This evaluation was focused on both quantitative (sensitivity, precision, and accuracy) and qualitative (identification capabilities) aspects. In the three instruments, the former facet was evaluated using selected reaction monitoring (SRM), which is the standard mode for quantitative LC-MS/MS analysis. Accuracy was similar in the three systems, with recoveries always over 70 %. Precision was better for the QqLIT and QqQ systems (7-15%) than for the IT system (10-17%). The QqLIT (working in SRM mode) and QqQ systems offered a linear dynamic range of at least 3 orders of magnitude, whereas that of the IT system was 2 orders of magnitude. The QqLIT system achieved at least 20-fold higher sensitivity than the QqQ system, and this was at least tenfold higher sensitivity than for the IT system. In the IT system, identification was based on sensitive full mass range acquisition and MS( n ) fragmentation and in the QqLIT system, it was based on the use of an information-dependent-acquisition scan function, which allows the combination of an SRM or MS full scan acting as the survey scan and an enhanced product ion scan followed by MS(3) as the dependent scan in the same analysis. Three instruments were applied to monitor the content in fish and shellfish (anchovies, swordfish, tuna, mussels, and oysters) obtained from Valencia and Barcelona markets (Spain). The eight target PFCs were detected at mean concentrations in the range from 10 ng kg(-1) (perfluoro-7-methyloctanoic acid and perfluoro-1-decanesulfonate) to 4,200 ng kg(-1) (perfluoropentanoic acid). Furthermore, perfluoroheptanoic and perfluoroundecanoic acids (not covered as target analytes) were identified in some samples.

A fully automated method has been developed for analysis of eighteen antibacterial compounds, including penicillins, cephalosporins and sulfonamides, in animal feed with limits of quantification in the range 0.25-5.79 microg kg(-1). The method is based on pressurized liquid extraction of 3 g homogenized feed with water and online clean-up of 500 microL of the extract with C(18)HD cartridges. The purified sample was directly analysed by liquid chromatography-electrospray tandem mass spectrometry (SPE-LC-ESI-MS-MS). Chromatographic separation was achieved within 10 min by use of a C(12) Phenomenex Hydro-RP reversed-phase analytical column and a mobile phase gradient (water + 0.1% formic acid-methanol + 0.1% formic acid). The method was validated, revealing capability for detection of concentrations as low as 0.09 microg kg(-1), decision limits (CCalpha) and detection capabilities (CCbeta) in the range 10-174 microg kg(-1) and 22-182 microg kg(-1), respectively, and inter-day precision ranging from 0.7 to 8.3%. Recovery, with internal standard correction, was in the range 93-134% for all analytes. The method was then applied to analysis of fifteen feed samples, nine of which contained at least one antimicrobial at concentrations between 0.006 and 1.526 mg kg(-1). The performance data and results from the method were compared with those from a previous method developed by our group, using offline SPE, by analyzing the same set of samples by both methods. The online SPE approach resulted in slightly improved sensitivity, with LODs of 0.09-2.12 microg kg(-1) compared with 0.12-3.94 microg kg(-1) by the offline approach. In general, better recovery was achieved by use of online purification (for 72% of the analytes) and the correlation between the two methods was good. The main advantages of the new online method are rapid and automated sample pre-treatment, and reduction of sample manipulation, enabling high-throughput analysis and highly accurate results. Because of all these characteristics, the proposed method is applicable and could be deemed necessary within the field of food control and safety.

This study presents the development and validation of a sensitive and fast (30 min extraction time and 10 min chromatographic run) method for the detection of penicillins, cephalosporins and sulfonamides in animal feed using pressurised liquid extraction and solid phase extraction as extraction and pre-concentration procedures, followed by liquid chromatography-quadrupole-linear ion-trap mass spectrometry. The developed method was validated showing limits of detection ranging from 0.12 (ampicillin) to 3.94 ng/g (amoxicillin), instrumental and analytical linearity coefficients above 0.99 in both standard and matrix-based solutions as well as relative recoveries ranging from 71% (cefoperazone) to 115% (cefazolin). Repeatability of the method was in the range of 1-9% (RSD %), whereas reproducibility ranged from 3% to 13% (RSD %). The developed and validated method was finally applied to the analysis of real feed samples. The results showed 10 out of 18 analytes to be present in at least one sample and all 14 samples to contain at least one analyte. Penicillin V, oxacillin, ceftiofur, cefoperazone, cefalexin, cefazolin, sulfamethoxypyridazine and sulfapyridine were not detected in any of the samples analysed. Considering the ban of antibacterials as growth promoters added in animal feed, this method is capable of detecting the low concentrations that could result from failure to comply with the regulations or on-site contamination.

A simple and sensitive method for simultaneous analysis of 43 pharmaceutical compounds in sewage sludge and sediment samples was developed and validated. The target compounds were extracted using pressurized liquid extraction (PLE) and then purified and pre-concentrated by solid phase extraction (SPE) using a hydrophilic-lipophilic balanced polymer. PLE extraction was performed on temperature of 100 degrees C, with methanol/water mixture (1/2, v/v) as extraction solvent. The quantitative analysis was performed by liquid chromatography tandem mass spectrometry using a hybrid triple quadrupole-linear ion trap mass spectrometer (LC-QqLIT-MS). Data acquisition was carried out in selected reaction monitoring (SRM) mode, monitoring two SRM transitions to ensure an accurate identification of target compounds in the samples. Additional identification and confirmation of target compounds were performed using the Information Dependent Acquisition (IDA) function. The method was validated through the estimation of the linearity, sensitivity, repeatability, reproducibility and matrix effects. The internal standard approach was used for quantification because it efficiently corrected matrix effects. Despite the strong matrix interferences, the recoveries were generally higher of 50% in both matrixes and the detection and quantification limits were very low. Beside the very good sensitivity provided by LC-QqLIT-MS, an important characteristic of the method is that all the target compounds can be simultaneously extracted, treated and analysed. Hence, it can be used for routine analysis of pharmaceuticals providing large amount of data. The method was applied for the analysis of pharmaceuticals in river sediment and wastewater sludge from three treatment plants with different treatment properties (i.e. capacity, secondary treatment, quality of influent waters). The analysis showed a widespread occurrence of pharmaceuticals in the sludge matrices.

This paper describes the development and validation of an analytical methodology to determine eight perfluorinated compounds (PFCs) in edible fish using pressurized liquid extraction (PLE) with water and solid-phase extraction (SPE) with an ion-exchanger as extraction and pre-concentration procedures, followed by liquid chromatography-quadrupole-linear ion trap mass spectrometry (LC-QqLIT-MS). The rapidity and effectiveness of the proposed extraction procedure were compared with those most commonly used to isolate PFCs from fish (ion-pairing and alkaline digestion). The average recoveries of the different fish samples, spiked with the eight PFCs at three levels (the LOQ, 10 and 100 microg kg(-1) of each PFC), were always higher than 85% with relative standard deviation (RSD) lower than 17%. A good linearity was established for the eight PFCs in the range from 0.003-0.05 to 100 microg kg(-1), with r>0.9994. The limits of quantification (LOQs) were between 0.003 and 0.05 microg kg(-1), which are well below those previously reported for this type of samples. Compared with previous methods, sample preparation time and/or LOQs are reduced. The method demonstrated its successful application for the analysis of different parts of several fish species. Most of the samples tested positive, mainly for perfluoropentanoic acid (PFPA), perfluorobutane sulfonate (PFBS) and perfluorooctanoic acid (PFOA) but other of the eight studied PFCs were also present.

A fully automated method for the detection of beta-lactam antibiotics, including six penicillins (amoxicillin, ampicillin, cloxacillin, dicloxacillin, oxacillin, and penicillin G) and four cephalosporins (cefazolin, ceftiofur, cefoperazone, and cefalexin) in bovine milk samples has been developed. The outlined method is based on online solid-phase extraction-liquid chromatography/electrospray-tandem mass spectrometry (SPE-LC/ESI-MS-MS). Target compounds were concentrated from 500 microL of centrifuged milk samples using an online SPE procedure with C18 HD cartridges. Target analytes were eluted with a gradient mobile phase (water + 0.1% formic acid/methanol + 0.1% formic acid) at a flow rate of 0.7 mL/min. Chromatographic separation was achieved within 10 min using a C-12 reversed phase analytical column. For unequivocal identification and confirmation, two multiple reaction monitoring (MRM) transitions were acquired for each analyte in the positive electrospray ionization mode (ESI(+)). Method limits of detection (LODs) in milk were well below the maximum residue limits (MRLs) set by the European Union for all compounds. Limits of quantification in milk were between 0.09 ng/mL and 1.44 ng/mL. The developed method was validated according to EU's requirements, and accuracy results ranged from 80 to 116%. Finally, the method was applied to the analysis of twenty real samples previously screened by the inhibition of microbial growth test Eclipse 100. This new developed method offers high sensitivity and accuracy of results, minimum sample pre-treatment, and uses for the first time an automated online SPE offering a high throughput analysis. Because of all these characteristics, the proposed method is applicable and could be deemed necessary within the field of food control and safety.

Pesticides are among the most detected contaminants in the aquatic environment. This is mainly due to their use in agriculture and their physico-chemical properties that enable transportation and a persistent or pseudo-persistent existence in the water media. Several directives and guidelines set maximum levels of pesticides in water in order to protect the human and environmental health. A brief discussion of the existing directives and guidelines concerning pesticides in water is presented, e.g., the new regulatory framework for the Registration, Evaluation and Authorisation of Chemicals (REACH), and the Directive 91/414/EEC concerning the placing of plant protection products on the market. Up-to-date analytical tools to support the REACH program are of prime importance to ensure its complete implementation. Since liquid chromatography (LC) coupled to mass spectrometry (MS) is considered the most appropriate technique for determination of most modern pesticides in environmental waters, the most recent developments and applications in this field are discussed in detail in this review.

This paper describes the determination and quantitation of hexabromocyclododecane (HBCD) enantiomers by liquid chromatography-quadrupole linear ion trap mass spectrometry (LC-QqLIT-MS). The method is based on the use of a chiral chromatographic column Nucleodex beta-PM (200 mm x 4.0 mm, 5 microm), which allows a good separation between HBCD enantiomers [(+/-)alpha, (+/-)beta and (+/-)gamma] in less than 15 min and the detection is performed by a Q-Trap instrument. Linearity was checked between 0.05 and 25 injected ng. Limits of detection (LODs) were in the range of 0.3-1.5 pg, limits of quantification (LOQs) were between 1 and 6 pg, and both values are lower than those published in the literature applying LC-MS-MS methods. The method was applied to sediment samples collected along the Cinca River, a tributary of the Ebro River (northeast of Spain). Samples were extracted and purified following a pressurized liquid extraction method. LODs of the method were between 0.12 and 5.61 ng/g and LOQs, from 0.38 to 1.87 ng/g. Total HBCD levels in these sediments ranged from not detected to 2660 ng/g dry weight. Enantiomeric fractions (EFs) were calculated and compared with EF obtained from standard injections. It is important to note that calculated EFs were corrected using (2)H(18)-labeled HBCD standards, in order to compensate matrix effect. EFs obtained in sediment samples suggested a higher presence of (+)alpha-HBCD and (+)gamma-HBCD in technical mixture, this suggests that it is not a racemic mixture.