157 research outputs found
Ecotoxicological effects and bioaccumulation of BPA analogues and their mixture in the clam Ruditapes philippinarum
Bisphenol A is recognized as an endocrine disruptor that can affect several biological processes in marine species. Consequently, its use has been restricted and it has been replaced with other similar compounds named bisphenol A analogues (BPA analogues). BPA analogues are speculatively considered safer compounds than BPA and their usage is increasing with a consequent higher environmental release. In this study, specimens of the clam Ruditapes philippinarum were exposed to three main BPA analogues, namely BPAF, BPF, BPS and their mixture at an environmentally relevant concentration of 300 ng/L for 7 and 14 days. Effects on biomarkers indicative of cytotoxicity, oxidative stress and damage and neurotoxicity were evaluated. In addition, bioaccumulation of the compound tested was analysed in clam soft tissues. Results showed that BPA analogues at an environment concentration affected cellular parameters and antioxidant system causing also oxidative damage, suggesting that BPA analogues can be harmful compounds for clams
Electrochemosensor for Trace Analysis of Perfluorooctanesulfonate in Water Based on a Molecularly Imprinted Poly(o-phenylenediamine) Polymer
This work is aimed at developing an electrochemical sensor for the sensitive and selective detection of trace levels of perfluorooctanesulfonate (PFOS) in water. Contamination of waters by perfluorinated alkyl substances (PFAS) is a problem of global concern due to their suspected toxicity and ability to bioaccumulate. PFOS is the perfluorinated compound of major concern, as it has the lowest suggested control concentrations. The sensor reported here is based on a gold electrode modified with a thin coating of a molecularly imprinted polymer (MIP), prepared by anodic electropolymerization of o-phenylenediamine (o-PD) in the presence of PFOS as the template. Activation of the sensor is achieved by template removal with suitable a solvent mixture. Voltammetry, a quartz crystal microbalance, scanning electron microscopy and elemental analysis were used to monitor the electropolymerization process, template removal, and binding of the analyte. Ferrocenecarboxylic acid (FcCOOH) has been exploited as an electrochemical probe able to generate analytically useful voltammetric signals by competing for the binding sites with PFOS, as the latter is not electroactive. The sensor has a low detection limit (0.04 nM), a satisfactory selectivity, and is reproducible and repeatable, giving analytical results in good agreement with those obtained by HPLC-MS/MS analyses
Low Level of Allergens in the Argentinean Plant Zuccagnia punctata Cav.: Screening and Quality Control of North-Western Propolis Using an LC-DAD-QTOF System
North-western Argentinean propolis (NAP), having promising bioactivity, was recently included into the National Food Code. Zuccagnia punctata Cav., a native shrub of north-western Argentina, is one of the prevalent botanical sources of NAPs, but no information on its allergenic constituents was available so far. A liquid chromatography-diode array detector -quadrupole-time of flight system (LC-DAD-QTOF) was used as a screening method for the reliable identification of sensitizing agents belonging to caffeic acid derivatives in Z. punctata and in two NAPs collected in the provinces of Catamarca and Tucum\ue1n. Caffeic acid phenethyl ester, one of the most active allergens in propolis, was never detected in either Z. punctata or NAP. Among 31 sensitizers, only geranyl caffeate was alleged in Z. punctata as <10% of its major constituent, whereas three caffeic acid derivatives with strong allergenic effect, i.e., geranyl, pentenyl, and benzyl caffeates, occurred in NAP samples (29%\u201336% of the Z. punctata major constituent), indicating other minor botanical sources. However, the high content of chalcones and flavonoids ascribed to Z. punctata significantly contributes to the antiallergenic and antioxidant character of these NAPs. This peculiar chemical profile depends on the extremophile condition in which this shrub grows and suggests other studies to characterize such raw materials for oral and topical formulation
Western Diet-Induced Metabolic Alterations Affect Circulating Markers of Liver Function before the Development of Steatosis
Since nutrition might have a significant impact on liver function, we analyzed the early effect of Western-type diet on hepatic tissue and lipid and drug metabolism in Wistar-Kyoto rats (n = 8); eight rats fed with a standard diet were used as controls. Histological analysis of liver tissue was performed, and plasma biochemical parameters were measured. Plasma concentration of six bile acids was determined by ultra-liquid chromatography-tandem mass spectrometry UHPLC-MS/MS. Hepatic gene expressions of enzymes involved in drug and lipid metabolism were assessed by means of real-time reverse transcription (qRT)-PCR. Liver of rats fed with a Western diet did not show macroscopic histological alterations, but number and diameter of lipid droplets increased, as well as DGAT1, GPAT4, SCD, FASN and SREBP2 expression. Furthermore, Western diet-fed animals showed an increase in the activation of hepatic stellate cells and macrophage number in liver tissue, as well as a significant increase in AST and bilirubin levels (p < 0.01), and in the LDL:HDL cholesterol ratio (p < 0.001). Plasma chenodeoxycholic acid concentration increased significantly, whereas cholic acid decreased (p < 0.05), and cytochrome P450 genes were generally downregulated. Significant changes in hepatic lipid and drug metabolism are early induced by the Western diet, prior to steatosis development. Such changes are associated with a peculiar alteration in circulating bile acids, which could represent an early marker of non-alcoholic fatty liver disease (NAFLD) development
Metallic functionalization of magnetic nanoparticles enhances the selective removal of glyphosate, AMPA, and glufosinate from surface water
Glyphosate (GLY) is the most used herbicide worldwide, raising concerns due to its toxicity and mobility in water. The concurrent spread of similar herbicides, i.e., glufosinate (GLUF) and aminomethylphosphonic acid (AMPA, a metabolite of GLY), also causes a serious concern to the environment. The application of magnetic nanoparticles (MNPs) gained wide attention as a promising approach for the environmental remediation of GLY. However, the fast agglomeration, low removal efficiency, and saturation of MNPs by non-target chemicals remain a challenge. Herein, we used polydopamine as a coating agent followed by functionalization with different metal ions, i.e. Ti(iv), Zr(iv), and Cu(ii), for selective removal of GLY, AMPA, and GLUF from deionised water in laboratory trials. Finally, we tested the performance of MNPs in surface waters contaminated with GLY at 0.17 & PLUSMN; 0.02 & mu;g L-1. The GLY removal efficiency (RE, %) of MNPs was optimized by using different GLY to MNP ratios and incubation times, in the presence of GLY-analogues and competitive species, i.e., phosphates. The results indicate that all metallic functionalized MNPs are more stable toward aggregation and effective in removing GLY than bare MNPs, up to 150 & mu;g L-1. The optimal ratio was 500 & mu;g(GLY) g(MNPs)(-1) (50 & mu;g GLY to 100 mg MNP), with RE > 80%. MNPs functionalized with Ti(iv) and Zr(iv) performed more efficiently than MNPs functionalized with Cu(ii), reaching an RE of 99.9% after a incubation time of 15 min. The presence of Ti(iv) and Zr(iv) in the MNPs increased the selectivity of the particles toward GLY and GLY analogues that can be removed with similar efficiency, and prevented competition with phosphates at much higher concentrations (1000 & mu;g L-1). Finally, GLY analogues can be easily re-eluted with ammonia, and the functionalized MNPs can be efficiently re-used up to four cycles. The use of metal-functionalized MNPs is a promising approach for the removal of target pollutants from contaminated water
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Methiocarb metabolites are systemically distributed throughout corn plants grown from coated seeds
Funder: UniversitĂ degli Studi di PadovaAbstract: Systemic insecticides such as neonicotinoids are widely used in seed coating practices for pest control in many crops, e.g., corn. Their success is due to their ability to protect the whole plant, from the roots to the upper leaves, but their use at high amounts is causing possible adverse effects on non-target animals exposed to contaminated pollen, nectar, leaves, and dust emitted during sowing. In 2018, the European Union banned some neonicotinoids and fipronil as seed coating insecticides in open fields. Consequently, the methylcarbamate methiocarb and less-toxic neonicotinoids, e.g., thiacloprid, have been authorized and largely used as alternative pesticides for corn seed coating. Here, an analytical protocol based on QuEChERS extraction/purification procedure and analysis by liquid chromatography-mass spectrometry has been optimized for the identification and the quantification of methiocarb, thiamethoxam, thiacloprid, and their metabolites in guttation drops, the xylem fluid excreted at leaf margins, and in leaves of corn plants grown from coated seeds. Although methiocarb is a non-systemic pesticide, we unexpectedly found high concentrations of its metabolites in both guttations and leaves, whereas methiocarb itself was below detection limits in most of the samples. The methiocarb main metabolite, methiocarb sulfoxide, was found at a mean concentration of 0.61 ± 1.12 ”g mLâ1 in guttation drops and 4.4 ± 2.1 ”g gâ1 in leaves. Conversely, parent compounds of neonicotinoids (thiamethoxam, thiacloprid) are systemically distributed in corn seedlings. This result raises safety concerns given that methiocarb sulfoxide is more toxic than the parent compound for some non-target species
Novel Correlations between Spectroscopic and Morphological Properties of Activated Carbons from Waste Coffee Grounds
Massive quantities of spent coffee grounds (SCGs) are generated by users around the world.
Different processes have been proposed for SCG valorization, including pyrolytic processes to achieve carbonaceous materials. Here, we report the preparation of activated carbons through pyrolytic processes carried out under different experimental conditions and in the presence of various porosity activators. Textural and chemical characterization of the obtained carbons have been achieved through BrunauerâEmmettâTeller (BET), ESEM, 13C solid state NMR, XPS, XRD, thermogravimetric and spectroscopic determinations. The aim of the paper is to relate these data to the preparation method, evaluating the correlation between the spectroscopic data and the physical and textural properties, also in comparison with the corresponding data obtained for three commercial activated carbons used in industrial adsorption processes. Some correlations have been observed between the Raman and XPS data
Biotransformation of nanoplastics in human plasma and their permeation through a model in vitro blood-brain barrier:An in-depth quantitative analysis
Challenges in characterizing and quantifying nanoplastics within the human body hinder understanding of their transport, biotransformation, and potential for cellular penetration and barrier crossing. By implementing an innovative analytical workflow, including incorporation of gadolinium (Gd) as a tracer into the polymer matrix of nanoplastics, the fate of nanoplastics relative to an in vitro blood-brain barrier (BBB) model is elucidated in the absence or presence of a biomomolecule corona. The nanoplastics were incubated in human plasma for 5 min, 1 h, 6 h, and 24 h, after which the absorbed proteins and lipids (biocorona) were determined. A total of 268 proteins were identified in the biological coronas on polystyrene (PS) and polyvinyl chloride (PVC) nanoplastics, with the initial compositions being broadly similar on both PS and PVC. Both nanoplastics exhibited a strong affinity for phosphatidylcholines (PC) and lysophosphocholines (LPC) from human plasma. The inherent chemical composition of the nanoplastics plays a pivotal role in the corona's evolution over time. Human induced pluripotent stem cell (iPSC)-derived endothelial cells (iECs) and astrocytes were exposed for 2 h to 5 ”g Lâ1 of pristine nanoplastics or nanoplastics covered with a biological corona (following incubation in plasma for 6 h). A relatively low concentration of PS and PVC nanoplastics was determined to be present within the cellular layer of the BBB. The number of PVC nanoplastics crossing the BBB was higher than the number of PS nanoplastics. The presence of a biological corona on these particles decreases their uptake and transcytosis. This understanding might further the development of preventive measures or therapeutic strategies to counteract potential nanoplastic-induced neurotoxicity, and provide a foundation for development of in silico models to predict the neurotoxic implications of nanoplastics.</p
A new processing scheme for ultra-high resolution direct infusion mass spectrometry data
High resolution, high accuracy mass spectrometry is widely used to characterise environmental or biological samples with highly complex composition enabling the identification of chemical composition of often unknown compounds. Despite instrumental advancements, the accurate molecular assignment of compounds acquired in high resolution mass spectra remains time consuming and requires automated algorithms, especially for samples covering a wide mass range and large numbers of compounds. A new processing scheme is introduced implementing filtering methods based on element assignment, instrumental error, and blank subtraction. Optional post-processing incorporates common ion selection across replicate measurements and shoulder ion removal. The scheme allows both positive and negative direct infusion electrospray ionisation (ESI) and atmospheric pressure photoionisation (APPI) acquisition with the same programs. An example application to atmospheric organic aerosol samples using an Orbitrap mass spectrometer is reported for both ionisation techniques resulting in final spectra with 0.8% and 8.4% of the peaks retained from the raw spectra for APPI positive and ESI negative acquisition, respectively.This work was supported by the European Research Council (ERC starting grant 279405) and by the U.K. Natural Environment Research Council (NERC grant NE/H52449X/1). ATZ thanks the Natural Sciences and Engineering Research Council of Canada, the Sir Winston Churchill Society of Edmonton, and the Cambridge Trust for PhD funding. IK was supported by a M. Curie Intra-European fellowship (project no. 254319
Non-target screening with high-resolution mass spectrometry: critical review using a collaborative trial on water analysis
In this article, a dataset from a collaborative nontarget
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 nontarget
analytical techniques are already substantially
harmonised between the participants, but the data processing
remains time-consuming. Although the objective of a Bfullyautomated
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.This work was supported in part by the SOLUTIONS project, which received
funding from the European Unionâs Seventh Framework Programme for
research, technological development and demonstration under Grant
Agreement No. 603437
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