Ultra-trace analysis of cyanotoxins by liquid chromatography coupled to high-resolution mass spectrometry

The increasing frequency of episodes of harmful algal blooms of cyanobacterial origin is a risk for ecosystems and human health. The main human hazard may arise from drinking water supply and recreational water use. For this reason, efficient multiclass analytical methods are needed to assess the level of cyanotoxins in water reservoirs and tackle these problems. This work describes the development of a fast, sensitive and robust analytical method for multiclass cyanotoxins determination based on dual solid-phase extraction (SPE) procedure using a polymeric cartridge first Oasis HLB (Waters Corporation, USA), and second, a graphitized non-porous carbon cartridge, SupelcleanTM ENVI-CarbTM (Sigma-Aldrich, USA), followed by ultra-high performance liquid chromatography high-resolution mass spectrometry (SPE-UHPLC-HRMS). This method enabled the analysis of cylindrospermopsin, anatoxin-a, nodularin and seven microcystins (MC-LR, MC-RR, MC-YR, MC-LA, MC-LY, MC-LW, MC-LF). The method limits of detection (MLOD) of the validated approach were between 4 and 150 pg/L. The analytical method was applied to assess the presence of the selected toxins in 21 samples collected in 3 natural water reservoirs in the Ter River in Catalonia (NE of Spain) used to produce drinking water for Barcelona city (Spain)

Analysis, levels and seasonal variation of cyanotoxins in freshwater ecosystems

Nutrient over-enrichment in freshwater environments, together with the on-going climate change, favour the toxin-producing cyanobacteria bloom. Human health hazard may arise from drinking contaminated water. Additionally, cyanobacterial blooms affect other economic areas such as tourism, recreation, commercial fishery, water management and monitoring. Nowadays there is a scarcity of information on seasonal variations of cyanotoxins in various regions. Understanding of historical trends and seasonal variation patters is a foundation for forecasting and will help to develop effective water management strategies. This review gives an overview of cyanotoxins' analysis and levels in freshwater environments with particular emphasis on seasonal variations in Europe. Recent analytical approaches are discussed and the seasonal patterns for three major European climate zones (Mediterranean, continental, and Atlantic) were distinguished. Additionally, data from multi-year studies showed a tendency of increasing cyanotoxins' levels

Suspect screening of natural toxins in surface and drinking water by high-performance liquid chromatography high-resolution mass spectrometry

Besides anthropogenic contamination, freshwater environments can also be affected by the presence of natural toxins. Mycotoxins, plant toxins and cyanotoxins are the most relevant groups that can be found in the aquatic system. However, until now, only cyanotoxins have been more carefully studied. In the present work, single workflow for the assessment of natural toxins in waters, based on suspect screening and target screening of a selected group of toxins is presented. The approach is based on a triple-stage solid-phase extraction (SPE) able to isolate a wide range of natural toxins of different polarities, followed by liquid chromatography coupled to high-resolution mass spectrometry (HPLC-ddHRMS2) using a Q-Exactive Orbitrap analyser. The acquisition was performed in full-scan (FS) and data-dependant acquisition (ddMS2) mode, working under positive and negative mode. For the tentative identification, different on-line databases such as ChemSpider and MzCloud and an in-house natural toxins list with 2384 structures, that includes cyanotoxins, plant toxins and mycotoxins, were used. Also, thanks to the MS2 data, it was possible to achieve a high level of tentative identification confidence, but confirmation was only possible comparing the standards of the suspected compounds. For those, the analytical parameters of the developed method were also validated, and the quantification was possible by external calibration. Validation showed recoveries in the range between 53 and 95 %, and method limits of detection (MDL) between 0.02 and 1.22 μg/L. This approach was applied to study natural toxins in 4 sampling sites along the Ter River in Catalonia (NE Spain). In this preliminary study 23 natural toxins were tentatively identified, and 9 of them confirmed (aflatoxin B1, anatoxin-a, nodularin, microcystin-LR, baicalein, kojic acid, cinchonine, B-asarone and atropine). The results of the quantification of these compounds showed concentrations below 1 μg/L in all cases, that is considered safe according to the actual legislation. This suspect screening approach allows a more comprehensive assessment of natural toxins in natural waters

Occurrence of C60 and related fullerenes in the Sava River under different hydrologic conditions

The presence of nanomaterials in the environment has caught the attention of the scientific because of the uncertainties in their fate, mobility and potential toxic effects. However, few studies have determined experimentally their concentration levels in aquatic systems up to date, which complicates the development of an adequate risk assessment. In the present study, the occurrence of ten fullerenes has been assessed in the Sava River (Southeastern Europe): 27 freshwater samples and 12 sediment samples from 12 sampling points have been analysed during two sampling campaigns. C was the most ubiquitous fullerene, with concentrations of 8 pg/l–59 ng/l and 108–895 pg/g in water and sediments, respectively. Statistically significant differences existed between the levels in 2014 and 2015, which has been attributed to the extreme hydrologic conditions (severe floods and drought, respectively). C fullerene has been detected in most of the samples and the fullerene derivatives [6,6]-phenyl C butyric acid methyl ester and N‑methyl fulleropyrrolidine have been detected eventually, which highlights that nanotechnology research and development activities are responsible for emitting these emerging contaminants to the environment. The role of diverse potential anthropogenic sources (including oil refinery, general industrial activity, river navigation, urban emissions and nanotechnology) is discussed

Contaminants of emerging concern in freshwater fish from four Spanish Rivers

This study investigated the occurrence of 135 contaminants of emerging concern (CECs) – pharmaceuticals, pesticides, a set of endocrine disrupting compounds (EDCs) (parabens, bisphenols, hormones, triazoles, organophosphorus flame retardants and triclosan), UV-filters, perfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs) – in 59 fish samples, collected in 2010 in 4 Spanish Rivers (Guadalquivir, Júcar, Ebro and Llobregat). Of the 135 CECs, 76 including 8 pharmaceuticals, 25 pesticides, 10 EDCs, 5 UV-filters, 15 PFASs and 13 HFRs were detected. Pharmaceuticals were the less frequently found and at lower concentrations. Pesticides, EDCs, UV-filters, PFASs and HFRs were detected more frequently (>50% of the samples). The maximum concentrations were 15 ng/g dry weight (dw) for pharmaceuticals (diclofenac), 840 ng/g dw for pesticides (chlorpyrifos), 224 ng/g dw for EDCs (bisphenol A), 242 ng/g dw for UV-filters (EHMC), 1738 ng/g dw for PFASs (PFHxA) and 64 ng/g dw for HFRs (Dec 602). The contaminants detected in fish are commonly detected also in sediments. In light of current knowledge, the risk assessment revealed that there was no risk for humans related to the exposure to CECs via freshwater fish consumption. However, results provide detailed information on the mixtures of CECs accumulated that would be very useful to identify their effects on aquatic biota.This research has been supported by the European Union 7th Framework Programme funding under Grant Agreement No. 603629-ENV-2013-6.2.1-Globaqua, by the Generalitat de Catalunya (Consolidated Research Groups 2017 SGR 1404 - Water and Soil Quality Unit) and by the Generalitat Valenciana (ANTROPOCEN@, PROMETEO/2018/155).Peer reviewe

Toxicity testing of wastewater and sewage sludge by biosensors, bioassays and chemical analysis

12 pages 4 figures, 3 tables.-- Printed version published May 2003.Toxicity testing has grown steadily in recent years, being a useful tool in environmental risk assessment. This review highlights different bioassays and recently developed biosensors based on acute toxicity measurements. Emphasis is placed on the use of combined approaches involving chemical analysis for the characterization and identification of complex toxic wastewater effluents and sewage sludge. Fractionation schemes that combine sample preparation and chemical analysis with biological measurements are presented and reviewed. Bioassay-directed chemical-analysis protocols involve solid phase extraction (SPE), followed by chromatographic techniques, such as liquid chromatography-mass spectrometry (LC-MS) or gas chromatography-mass spectrometry (GC-MS). Toxicity testing is carried out by either bioluminescence inhibition methods or a whole-cell bacterial biosensor. Other biological toxicity tests are also reviewed. Examples of using different bacterial acute toxicity assays are presented for phenols, polyethoxylate surfactants, linear alkyl benzene sulphonates (LASs), naphthalene and benzene sulphonates, polycyclic aromatic hydrocarbons (PAHs), pesticides and pharmaceutical drugs.This work was supported by Quality of Life and Management of Living Resources European Union Program (Evaluation/Validation of Novel Biosensors in Real Environmental and Food Samples, Contract No. QLK-CT2000-01311) and the Ministerio de Ciencia y Tecnologia (PPQ2001-1805-CO3-01).Peer reviewe

Analytical methodologies for the detection of β-lactam antibiotics in milk and feed samples

Antibiotic residues in milk are of great concern to dairy farmers, milk processors, regulatory agencies and consumers. In addition, the effectiveness of antibiotics is threatened by extensive, inappropriate use. In veterinary practice, antibiotics are utilized at therapeutic levels primarily to treat diseases and to prevent infections. They are also used at sub-therapeutic levels to increase feed efficiency and to promote growth in food-producing animals. The frequent, sometimes illegal, use of antibiotics may result in residues being found at different concentration levels in products of animal origin, such as milk. β-lactams comprise some of the antibiotics most frequently used for the treatment of sick animals in Europe. This review presents analytical methods that have been developed during the past decade for penicillin and cephalosporin residues in milk and feed samples. It includes microbiological approaches, biosensors, immunochemical techniques and chromatographic methods. © 2009 Elsevier Ltd. All rights reserved.The work described in this article was supported by the EU through the CONffIDENCE project (Contract No. 211326). The Spanish Government is acknowledged for financial support (FI 2009). This article reflects only the authors’ views, and the EU is not liable for any use that may be made of the information contained therein.Peer Reviewe