A5032328459- Analytical Chemistry and Chromatography
- Petroleum Processing and Analysis
- Metabolomics and Mass Spectrometry Studies
- Mass Spectrometry Techniques and Applications
- Advanced Chemical Sensor Technologies
- Molecular Sensors and Ion Detection
- Hydrocarbon exploration and reservoir analysis
- Phase Equilibria and Thermodynamics
- Analytical chemistry methods development
- Microbial Metabolic Engineering and Bioproduction
- Spectroscopy and Chemometric Analyses
- Minerals Flotation and Separation Techniques
- Chemical Thermodynamics and Molecular Structure
- Catalysis and Hydrodesulfurization Studies
- Protein Interaction Studies and Fluorescence Analysis
- Viral Infectious Diseases and Gene Expression in Insects
- Microfluidic and Capillary Electrophoresis Applications
- Analytical Chemistry and Sensors
- Advanced Physical and Chemical Molecular Interactions
- Carcinogens and Genotoxicity Assessment
- Effects and risks of endocrine disrupting chemicals
- Scientific Measurement and Uncertainty Evaluation
- Environmental Chemistry and Analysis
- Fullerene Chemistry and Applications
- Cancer, Hypoxia, and Metabolism
Universidad de Zaragoza
1999-2023
Instituto de Carboquímica
1995-2013
Consejo Superior de Investigaciones Científicas
2000-2013
University of the Basque Country
2000-2006
Instituto Politécnico Nacional
2002
University of Cincinnati
2000-2001
Abstract The European Commission asked EFSA to review whether the authorisation of N,N‐bis(2‐hydroxyethyl)alkyl(C8‐C18)amine (FCM No 19) and hydrochlorides 20) is still in accordance with Regulation (EC) 1935/2004, as provided for Article 12(3). FCM Panel concluded that some uses substance are not this Regulation, since migration likely exceed current SML(T) 1.2 mg/kg food under certain conditions use. Based on data, 19, N,N‐bis(2‐hydroxyethyl)alkyl(C8‐C18)amine, safety concern consumer if...
Journal Article Quantitative Hydrocarbon Group Type Analysis of Petroleum Hydroconversion Products Using an Improved TLC-FID System Get access Jesús Vela, Vela Departamento de Procesos Químicos, Instituto Carboquímica, CSIC, Calle Poeta Luciano Gracia 5, 50015 Zaragoza, Spain Search for other works by this author on: Oxford Academic PubMed Google Scholar Vicente L. Cebolla, Cebolla * *Author to whom correspondence should be addressed. Luis Membrado, Membrado José M. Andrés Chromatographic...
Fluorescence enhancement of a broad variety solutes has been used extensively in TLC although no thorough explanation proposed. In this work, we try to understand it and explore new applications which can be put. way, alkanes quantitatively determined by fluorescence scanning densitometry using silica gel plates impregnated with berberine sulfate. Molecular simulation analysis molecular orbitals allows phenomenon explained case lays the groundwork explain enhancements produced other...
Direct application of the fluorescence response enhancement (derived from interaction berberine cation with saturated hydrocarbons) to petrochemical analysis is achieved. Hydrocarbon types are successfully determined in middle (gasoil) and heavy (lubricants, vis-breaking fuel, oil) petroleum distillates adequate precision sensitivity. The novelty this method resides fact that a single scanning only needed for determination saturates aromatics same chromatogram. In spite their chemical...
This work is a review on HPTLC contribution to lipid analysis in complex matrices, the period from 2010 now, lapse of time where hyphenation with other techniques, especially Mass Spectrometry, has experienced an important growth. Scanning densitometry (SD)-UV/FL separated lipids, as core detection and centerpiece for hyphenation, its coupling MS using soft ionization techniques (ESI, APCI, MALDI, DESI others), are central axis this work. The occasional intercalation on-plate biological...
Alkanes in the presence of berberine sulfate provide an enhancement fluorescent signal, which depends on alkane concentration and structure, when system is irradiated with monochromatic UV light. Computational analysis suggests that ion-induced dipole between alkanes responsible for this phenomenon. This interaction can properly model experimentally obtained response. The proposed explanation allows other interacting systems to be designed, have been confirmed.
Many chemical compounds, including nonfluorescent ones, induce changes in the fluorescence spectra of certain probes, such as berberine cation and Reichardt's betaine, both absence presence solvent, that affect almost exclusively emission intensity. In this work, application detection by intensity (FDIC) to HPLC TLC chromatographic systems with detectors has been studied. FDIC is special interest detecting analytes, either or mode. It does not involve covalent interactions, dielectric...
Soxtec, a medium-cost extraction apparatus, was tested against classical Soxhlet applied to coal and coal-derived products. An optimization study of Soxtec operating conditions for our samples led reduction 90% in the total time needed by Soxhlet, with comparable repeatability results similar yields. As share common set general conditions, product composition is very similar, most differences can be explained terms increased efficiency probably due better mass transfer. A multistep procedure...
Polycyclic aromatic compounds (PACs) with molecular weights lower than 300 were not considered in the past to be analyzable using an evaporative light-scattering detector (ELSD) due exclusively their supposed volatility. We demonstrate that a variety of small, low-boiling, 3–6-ringed PACs (which include condensed PAHs, heteronuclear polycyclic compounds, and hydroxy-PAHs) can analyzed ELSD under mild working conditions without significant volatilization. Although area counts versus sample...
Time-consuming external standard-based calibration methods are usually performed for hydrocarbon group type analysis (HGTA) of fossil fuels, regardless the instrumental chromatographic technique. In this work, HGTA a broad variety coal and petroleum products is using modern thin-layer chromatography-flame ionization detection (TLC-FID) system rapid method based on internal normalization. Repeatability, linear intervals, sample load ranges quantitative application detailed different that...
Continuous free flow electrophoresis was investigated as a tool for the preparative chiral separation of piperoxan using sulfated cyclodextrin additive. In absence additive, sample stream deflected cathodically. However, presence in run buffer caused anodic deflection and splitting into two streams, each enriched one enantiomer. Although used comprised mixture homologues isomers, this polydispersity did not seem to significantly impact band dispersion. Sample introduction rates ranged from...
High-performance thin-layer chromatography (HPTLC)-densitometry was directly combined with electrospray (ESI) tandem mass spectrometry for obtaining rapid and relevant structural identification of phospholipids (PL) species associated to membrane proteins (MP), in non-sulfur, purple bacteria having photosynthetic activity. Thus, belonging phosphatidylcholines (PC), phosphatidylethanolamines (PE), cardiolipins (CL) phosphatidylglycerols (PG) MP were investigated bacterial extracts from...
Controversy exists concerning quantitation using thin-layer chromatography-flame ionization detection (TLC-FID). Inadequate sample selections and detector designs the non-uniformity of chromarods have been blamed for some confusing results. In this paper, performances a modern TLC-FID system (which includes newest configuration) are tested on polycyclic aromatic compound standards related compounds as preliminary step to evaluate its suitability quantitative hydrocarbon group type analysis...
Different methodologies based on thin-layer chromatography (TLC)/densitometry were used to separate and quantitate hydrocarbon types in middle distillates (gas oil), heavy (lubricant) from petroleum, coal-derived products. Thus, petroleum products separated into saturates aromatics by development, using n-hexane (9 min) followed dichloromethane (4.5 min), of silica gel plates impregnated with berberine sulfate. Detection was performed fluorescence scanning 365 nm as the excitation...
A combined hydride-generation/gas-phase chemiluminescence (HG-GPCL) method for the determination of arsenic(III) and antimony(III) by using a conventional luminometer is proposed. The was optimized in terms type reaction chamber, instrumental settings, hydride generation conditions used. It provides linear response to As(III) Sb(III) above concentration 0.05 0.50 mg L −1 , respectively, with relative standard deviation ∼3% both species. Arsenic antimony can thus be determined simultaneously...