Search results for "Spectrometry"
showing 10 items of 3206 documents
The Assessment of Heavy Metal Contamination of the Cultivated Soils in the Odra River Floodplain
2021
Abstract The aim of the study was to assess the contamination of selected heavy metals in cultivated soils of the Odra river floodplain. The heavy metals Mn, Fe, Cu, Zn, Ni, Cd and Pb were determined in soil samples collected in the autumn of 2020 - after the vegetation period of plants from designated measurement points. Concentrations of the analytes were measured using an atomic absorption spectrometer (F-ASA). A comparison was made between concentrations of heavy metals in soil samples collected from areas flooded in 1997 and from areas flooded as a result of rainfall, snowmelt and winter floods. The results of the studies were compared with the data for soils taken from non-flooded are…
Synthesis and characterization of a novel high luminescent gold-2-mercapto-1-methyl-imidazole complex
2010
Synthesis and characterization of a new gold-2-mercapto-1-methyl imidazole are reported. This new organic material shows an extraordinary fluorescence activity (superfluorescence) up to 220°C with an unusual quantum yield of 0.2. Both fluorescence and NMR spectroscopy were applied to understand the behavior of the gold-2-mercapto-1-methylimidazole complex. Results suggest that the superfluorescence activity can be attributed to the shrinking of the HOMO-LUMO band gap energy following complexation of the organic imidazole system with gold. Copyright © 2010 John Wiley & Sons, Ltd.
Impact of a Pitanga Leaf Extract to Prevent Lipid Oxidation Processes during Shelf Life of Packaged Pork Burgers: An Untargeted Metabolomic Approach
2020
In this work, the comprehensive metabolomic changes in pork burgers treated with different antioxidants, namely, (a) a control without antioxidants, (b) 200 mg/kg butylated hydroxytoluene (BHT), and (c) 250 mg/kg pitanga leaf extract (PLE, from Eugenia uniflora L.), each one packaged under modified atmosphere (80% O2 and 20% CO2) for 18 days storage at 2 ±
Heat treatment of vegetable oils. II. GC-MS and GC-FTIR spectra of some isolated cyclic fatty acid monomers
1987
Gas liquid chromatography coupled with mass spectrometry (GC-MS) showed that the cyclic fatty acid monomers (CFAM) isolated from a heated linseed oil have two ethylenic bonds, while the CFAM isolated from heated sunflower oils were saturated and monoethylenic isomers. GC-MS studies also showed the presence of cyclohexenic derivatives in the case of linseed oil.
Identification by GC-FID and GC-MS of amino acids, fatty and bile acids in binding media used in works of art.
2001
GC-FID was used as single methodology for the identification and differentiation of proteins, lipids and ox bile from binders used in artistic paintings. The samples were hydrolyzed by HCl. Subsequently, the simultaneous formation of volatile derivatives of the amino, fatty and bile acids with ethyl chloroformate was performed quickly and safely in an aqueous medium. The derivatives were separated by capillary GC and characterized by GC-MS. The ageing of drying oils was studied, identifying pelargonic acid among other degradation products. Proteinaceous and lipoid binding media were characterized by means of the quotients between the areas of the peaks for each amino or fatty acid with resp…
Gas chromatographic and mass spectrometric characterization of the organic acids extracted from some preparations containing lyophilized royal jelly.
2009
Thirty-five aliphatic acids were identified by gas chromatography-mass spectrometry from the ether extract of commercial preparations containing lyophilized royal jelly. The article presents linear-programmed retention indices on capillary columns with non-polar and low-polar stationary phases and mass spectra for identified compounds which were not characterized earlier by these parameters. Nine compounds are reported for the first time as royal jelly constituents.
Ageing behaviour and analytical characterization of the Jatobá resin collected from Hymenaea stigonocarpa Mart.
2009
Abstract This paper reports the results of an analytical study to characterize the trunk resin collected from the Hymenaea stigonocarpa Mart. species from the region of Minas Gerais (Brazil), popularly known as Jatoba resin. Hymenaea resins are reported to have been used in artistic applications such as protective varnishes in polychromed sculptures and paintings. Therefore, the identification of the main chemical changes that take place in the resin when it is prepared as a thin film exposed to atmospheric effects have been considered herein. Changes due to the degradation effect of light have been studied on a series of specimens prepared as a thin films and subjected to accelerated UV li…
Chemical variability in the essential oil of Cinnamomum tamala L. leaves from India.
2011
The chemical composition of the essential oils obtained from the fresh leaves of Cinnamomum tamala Nees et Eberm. was determined by GC and GC–MS. The yield of the oil on a dry weight basis ranged from 1.2% to 3.9% (w/w). Phenyl propanoids constitute the major portion (88.9–95.0%) of the oils. Fifty-four compounds were identified from the oils. Eugenol (91.4–41.8%) was the main compound, followed by eugenyl acetate (0.0–47.1%) and α-phellandrene (0.6–2.5%) in the analysed oils.
Involvement of an Alkane Hydroxylase System of Gordonia sp. Strain SoCg in Degradation of Solid n-Alkanes▿
2010
ABSTRACT Enzymes involved in oxidation of long-chain n -alkanes are still not well known, especially those in Gram-positive bacteria. This work describes the alkane degradation system of the n -alkane degrader actinobacterium Gordonia sp. strain SoCg, which is able to grow on n -alkanes from dodecane (C 12 ) to hexatriacontane (C 36 ) as the sole C source. SoCg harbors in its chromosome a single alk locus carrying six open reading frames (ORFs), which shows 78 to 79% identity with the alkane hydroxylase (AH)-encoding systems of other alkane-degrading actinobacteria. Quantitative reverse transcription-PCR showed that the genes encoding AlkB (alkane 1-monooxygenase), RubA3 (rubredoxin), RubA4…
Isolation of Gram-positive n-alkane degraders from a hydrocarbon-contaminated Mediterranean shoreline.
2007
Aims: To investigate the petroleum hydrocarbon (HC)-degrading potential of indigenous micro-organisms in a sandy Mediterranean coast, accidentally contaminated with petroleum-derived HCs. Methods and Results: Using culturable methods, a population of Gram-positive n-alkane degraders was detected in the contaminated soil. Five isolates, identified as one Nocardia, two Rhodococcus and two Gordonia strains, were able to degrade medium- and long-chain n-alkanes up to C36 as assessed by growth assays and gas chromatography-mass spectrometry analysis. Diverging alkane hydroxylase-encoding genes (alkB) were detected by PCR, using degenerated primers, in all the strains; multiple sequences were obt…