ORCID Profile
0000-0001-5582-5446
Current Organisation
Universidade Nova de Lisboa
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Publisher: Elsevier BV
Date: 15-05-2007
DOI: 10.1016/J.TALANTA.2006.12.040
Abstract: Two advanced oxidation processes (AOPs), based on high-intensity focused ultrasound (HIFU), namely, KMnO(4)/HCl/HIFU and H(2)O(2)/HCl/HIFU are studied and compared for the determination of toxic arsenic in human urine [As(III)+As(V)+MMA+DMA] by flow-injection hydride-generation atomic absorption spectrometry (FI-HG-AAS). The KMnO(4)/HCl/HIFU procedure was found to be adequate for organic matter degradation in human urine. l-cysteine (letra minuscula) was used for As reduction to the trivalent state. The new procedure was assessed with seven urines certified in different As species. Results revealed that with KMnO(4)/HCl/HIFU plus l-cysteine the toxic arsenic can be accurately measured in human urine whilst the H(2)O(2)/HCl/HIFU procedure underestimates toxic As. DMA and MMA degradation in urine were observed, due to the effects of the ultrasonic field. Recoveries for As(III), As(V), MMA and DMA were within the certified ranges. Arsenobetaine was not degraded by the AOPs. The new procedure adheres well to the principles of analytical minimalism: (i) low reagent consumption, (ii) low reagent concentration, (iii) low waste production and (iv) low amount of time required for s le preparation and analysis.
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.TALANTA.2013.12.054
Abstract: Ultrasonic energy is gaining momentum in Proteomics. It helps to shorten many proteomics workflows in an easy and efficient manner. Ultrasonic energy is nowadays used for protein extraction, solubilisation and cell disruption, to speed protein identification, protein quantification, peptide profiling, metal-protein complexes characterisation and imaging mass spectrometry. The present review gives a perspective of the latest achievements in ultrasonic-based s le treatment for proteomics as well as provides the basic concepts and the tools of the trade to efficiently implement this tool in proteomics labs.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 20-10-2017
Abstract: Hydrogen migration between adjacent carbons is widespread in the reaction mechanisms of organic chemistry. DeVine et al. used photoelectron spectroscopy to discern the quantum mechanical underpinnings of this 1,2 shift in a prototypical case: conversion of vinylidene (H 2 CC) to acetylene (HCCH). The technique probed specific states of vinylidene by ejecting electrons with varying energies from a negative ion precursor. Experimental data and accompanying theoretical simulations pinpointed a vibrational rocking mode that facilitated the migration. Replacement of hydrogen with its heavier deuterium isotope disrupted this pathway. Science , this issue p. 336
Location: Portugal
Location: No location found
Location: Portugal
No related grants have been discovered for Carlos Lodeiro.