Cobalt-Based Catalysts for CO Preferential Oxidation

In this work, catalysts based on cobalt supported on ZrO2 and CeO2 and CoCeMnOx were studied for the CO preferential oxidation (COPrOx) in hydrogen-rich stream able to feed fuel cells. Among them, the CoCeMnOx formulation showed the highest CO conversion at low temperatures, while the cobalt oxide supported on ceria presented the best selectivity toward CO2. The Co3O4 spinel was the active phase for the CO preferential oxidation detected in all catalysts. However, the CoOx-CeO2 and CoCeMnOx catalysts resulted more active than cobalt oxide supported on zirconia. The presence of ceria close to cobalt species promotes the redox properties and enhances the catalytic activity. In the CoCeMnOx catalyst prepared by coprecipitation, the incorporation of Mn represented an additional positive effect. The presence of Mn promoted the reoxidation of Co2+ to Co3+ and, consequently, the activity increased at low temperature. By X-ray diffraction (XRD) of CoOx-ZrO2 and the CoOx-CeO2 catalysts, the Co3O4 spinel and ZrO2 or CeO2 were identified in agreement with laser-Raman spectra. At the same time, the CoCeMnOx catalyst, prepared by coprecipitation of precursor salts, showed an incipient development of a new phase (Mn,Co)3O4 mixed spinel, due to the intimate contact between elements

Investigation of cannabis biomarkers and transformation products in waters by liquid chromatography coupled to time of flight and triple quadrupole mass spectrometry

11-Nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) is commonly selected as biomarker for the investigation of cannabis consumption through wastewater analysis. The removal efficiency of THC-COOH in wastewater treatment plants (WWTPs) has been reported to vary between 31% and 98%. Accordingly, possible transformation products (TPs) of this metabolite might be formed during treatment processes or in receiving surface water under environmental conditions. In this work, surface water was spiked with THC-COOH and subjected to hydrolysis, chlorination and photo-degradation (both ultraviolet and simulated sunlight) experiments under laboratory-controlled conditions. One hydrolysis, eight chlorination, three ultraviolet photo-degradation and seven sunlight photo-degradation TPs were tentatively identified by liquid chromatography coupled to quadrupole time-of-flight mass spectrometer (LC-QTOF MS). In a subsequent step, THC-COOH and the identified TPs were searched in wastewater samples using LC coupled to tandem mass spectrometry (LC–MS/MS) with triple quadrupole. THC-COOH was found in all influent and effluent wastewater samples analyzed, although at significant lower concentrations in the effluent samples. The removal efficiency of WWTP under study was approximately 86%. Furthermore, THC-COOH was also investigated in several surface waters, and it was detected in 50% of the samples analyzed. Regarding TPs, none were found in influent wastewater, while one hydrolysis and five photo-degradation (simulated sunlight) TPs were detected in effluent and surface waters. The most detected compound, resulting from sunlight photo-degradation, was found in 60% of surface waters analyzed. This fact illustrates the importance of investigating these TPs in the aquatic environment

The mineralocorticoid receptor plays a transient role in mouse skin development

3 páginas, 2 figuras. Contiene material suplemenarioGlucocorticoid (GC) hormones can bind two structurally and functionally related steroid receptors: the GC Receptor (GR or Nr3c1) and the mineralocorticoid receptor (MR or Nr3c2), which recognize the same DNA response elements and act as ligand-dependent transcription factors. While the crucial role of GR for skin homeostasis has been widely characterized, the exact role of MR in this tissue deserves further study. We assessed NR3C2 expression in developing and adult WT mouse skin and found a transient peak at embryonic day (E)16.5, which along with low levels of HSD11B2, the enzyme inactivating GCs, supports a role for GC-MR complexes in epidermal maturation. Consistent with this observation, MR-/- embryonic skin showed alterations in early epidermal differentiation that resolved postnatally. The lack of a more severe skin phenotype of MR-/- mice suggests functional compensation by GR in this tissue in the perinatal period.This work was supported by JSPS KAKENHI grant numbers 25870545 and 15K09772. Spanish Ministerio de Ciencia e Innovación. Grant Numbers: SAF2011-28115, SAF2014-59474-RPeer Reviewe

Qualitative screening of 116 veterinary drugs in feed by liquid chromatography-high resolution mass spectrometry. Potential application to quantitative analysis

Veterinarian and human pharmaceuticals may be intentionally added to animal feed to enhance animal production. Monitoring these substances is necessary for protecting the consumers. In this work, a screening method covering 116 human and veterinary drugs has been developed and validated in five types of animal feed at 0.02 and 0.2 mg kg−1. After a simple extraction and dilution, the samples were analysed by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS). Nearly all compounds tested were detected at 0.02 mg kg−1, based on the presence of the accurate-mass (de)protonated molecule. However, the identification using a second accurate-mass ion was more problematic at this level. Finally, the procedure was applied to 22 feed samples, where trimethoprim, robenidine, or α- and β-nandrolone were detected and identified. The potential applicability of the method to quantitative analysis of the compounds detected in the samples was also evaluated

Investigation of degradation products of cocaine and benzoylecgonine in the aquatic environment

In this work, ultra-high-performance liquid chromatography (UHPLC) coupled to a hybrid quadrupole time-of-flight mass spectrometer (QTOF MS) has allowed the discovery and elucidation of degradation products of cocaine and its main metabolite benzoylecgonine (BE) in water. Spiked surface water was subjected to hydrolysis, chlorination and photo-degradation (both ultraviolet irradiation and simulated sunlight). After degradation of cocaine, up to sixteen compounds were detected and tentatively identified (1 resulting from hydrolysis; 8 from chlorination; 7 from photo-degradation), three of which are well known cocaine metabolites (BE, norbenzoylecgonine and norcocaine). Regarding BE degradation, up to ten compounds were found (3 from chlorination; 7 from photo-degradation), including one known metabolite (norbenzoylecgonine). Since reference standards were available for the major metabolites, they could be confirmed using information on retention time and fragment ions. The other degradates resulted from chlorination, dealkylation, hydroxylation and nitration, or from a combination of these processes. Several influent and effluent sewage water, and surface water samples were then screened for the identified compounds (known and unknown) using UHPLC–tandem MS with triple quadrupole. BE, norcocaine and norbenzoylecgonine were identified in these samples as major metabolites. Four previously unreported degradates were also found in some of the samples under study, illustrating the usefulness and applicability of the degradation experiments performed in this work

Identification of new omeprazole metabolites in wastewaters and surface waters

Omeprazole is one of the world-wide most consumed pharmaceuticals for treatment of gastric diseases. As opposed to other frequently used pharmaceuticals, omeprazole is scarcely detected in urban wastewaters and environmental waters. This was corroborated in a previous research, where parent omeprazole was not detected while four transformation products (TPs), mainly resulting from hydrolysis, were found in effluent wastewaters and surface waters. However, the low abundance of omeprazole TPs in the water samples together with the fact that omeprazole suffers an extensive metabolism, with a wide range of excretion rates (between 0.01 and 30%), suggests that human urinary metabolites should be investigated in the water environment. In this work, the results obtained in excretion tests after administration of a 40 mg omeprazole dose in three healthy volunteers are reported. Analysis by liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF MS) reported low concentrations of omeprazole in urine. Up to twenty-four omeprazole metabolites (OMs) were detected and tentatively elucidated. The most relevant OM was an omeprazole isomer, which obviously presented the same exact mass (m/z 346.1225), but also shared a major common fragment at m/z 198.0589. Subsequent analyses of surface water and effluent wastewater samples by both LC-QTOF MS and LC-MS/MS with triple quadrupole revealed that this metabolite (named as OM10) was the compound most frequently detected in water samples, followed by OM14a and OM14b. Up to our knowledge, OM10 had not been used before as urinary biomarker of omeprazole in waters. On the contrary, parent omeprazole was never detected in any of the water samples. After this research, it seems clear that monitoring the presence of omeprazole in the aquatic environment should be focused on the OMs suggested in this article instead of the parent compound

Study of cyanotoxin degradation and evaluation of their transformation products in surface waters by LC-QTOF MS

In the present work, the degradation of three cyanotoxins from the hepatotoxins group was investigated under laboratory-controlled experiments in water samples. Surface waters spiked with microcystin-LR (MC-LR), nodularin (NOD) and cylindrospermopsin (CYN) were subjected to hydrolysis, chlorination and photo-degradation, under both sunlight (SL) and ultraviolet (UV) radiation. A total of 12 transformation products (TPs) were detected and tentatively identified by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF MS). These comprised: 6 chlorination TPs (3 from CYN and 3 from MC-LR, 2 isomers); 4 UV TPs (all from CYN); and 2 sunlight TPs (one isomer from MC-LR and another from NOD). No TPs were observed under hydrolysis conditions. The chemical structures for all TPs were tentatively proposed based on the accurate-mass QTOF MS full-spectra. Analysis of real-world samples collected from the Peñol reservoir (Antioquia, Colombia) revealed the presence of MC-LR and CYN as well as a sunlight TP identified in the laboratory experiments. Data presented in this article will assist further research on TPs potentially formed in future tertiary degradation processes applied for the removal of organic micro-pollutants in water; as well as improving available knowledge on the toxic implications of cyanobacterial toxins TPs in surface waters

Fast determination of 40 drugs in water using large volume direct injection liquid chromatography–tandem mass spectrometry

This work describes a rapid analytical method based on direct sample injection of water samples for the simultaneous identification/quantification of 40 emerging compounds, including pharmaceuticals and drugs of abuse. The water samples were analyzed by ultra-high-performance liquid chromatography coupled to hybrid triple quadrupole mass spectrometer (UHPLC–MS/MS QqQ). Taking profit of the increasing sensitivity of nowadays tandem mass spectrometers, direct sample injection of large volumes has been an attractive alternative to pre-concentration steps. In this work, the developed methodology has been validated at three concentration levels (10, 100 and 1000 ng/L) in 10 different water samples of different types (5 effluent wastewater and 5 surface water samples). The majority of compounds could be satisfactory validated at these concentrations, showing good recoveries and precision. With only few exceptions, the limits of quantification (LOQs), estimated from the sample chromatogram at lowest spiked level tested, were below 3 ng/L. The method was applied to the analysis of 10 effluent wastewater and 10 surface water samples. Venlafaxine was the compound most frequently detected (80%) in surface water, followed by acetaminophen (70%). Regarding effluent wastewater, valsartan and 4-acetyl aminoantipyrine were detected in 9 out of 10 samples analyzed. These two compounds together with 4-formyl aminoantipyrine and naproxen showed the highest concentrations (>2000 ng/L). In these cases, a dilution step was required for a correct quantification. As an additional evaluation of the method performance, the same water samples were analyzed in another laboratory by a second analytical methodology, based on on-line solid-phase-extraction coupled to LC–MS/MS (QqQ).The authors are very grateful to Serveis Centrals d׳Instrumentació Científica (SCIC) of University Jaume I for using the Xevo TQS mass spectrometer. The financial support of the Centro de Desarrollo Tecnológico Industrial (CDTIIDI-20110823/EXP00044257), of the Spanish Ministry of Education and Science (Ref CTQ2012-36189) and of Generalitat Valenciana (research group of excellence PROMETEO/2009/054; Collaborative Research on Environment and Food Safety, ISIC/2012/016) is acknowledged

Deep subcutaneous application of poly-L-lactic acid as a filler for facial lipoatrophy in HIV-infected patients

Introduction: Facial lipoatrophy is a crucial problem of HIV-infected patients undergoing highly active antiretroviral therapy (HAART). Poly-L-lactic acid (PLA), provided as New-Fill(R)/Sculptra(TM), is known as one possible treatment option. In 2004 PLA was approved by the FDA as Sculptra(TM) for the treatment of lipoatrophy of the face in HIV-infected patients. While the first trials demonstrated relevant efficacy, this was to some extent linked to unwanted effects. As the depth of injection was considered relevant in this context, the application modalities of the preparation were changed. The preparation was to be injected more deeply into subcutaneous tissue, after increased dilution. Material and Methods: To test this approach we performed a pilot study following the new recommendations in 14 patients. Results: While the efficacy turned out to be about the same, tolerability was markedly improved. The increase in facial dermal thickness was particularly obvious in those patients who had suffered from lipoatrophy for a comparatively small period of time. Conclusion: With the new recommendations to dilute PLA powder and to inject it into the deeper subcutaneous tissue nodule formation is a minor problem. However, good treatment results can only be achieved if lipoatrophy is not too intense; treatment intervals should be about 2 - 3 weeks. Copyright (C) 2005 S. Karger AG, Basel