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1.
J Environ Monit ; 8(12): 1219-26, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17133278

RESUMO

The present paper reports on a rapid method for the analysis of gaseous emissions from ceramic industry, based on ion mobility spectrometry (IMS) as a means for on-site monitoring of volatile organic compounds (VOCs) produced during tile baking. IMS was calibrated with a set of reference compounds (i.e. ethyl acetate, ethanol, ethylene glycol, diethylene glycol, acetaldehyde, formaldehyde, 2-methyl-1,3-dioxolane, 2,2-dimethyl-1,3-dioxolane, 1,3-dioxolane, 1,4-dioxane, benzene, toluene, cyclohexane, acetone, acetic acid) via air-flow permeation. The technique was tested on a laboratory-scale kiln and tiles prepared with selected glycol- and resin-based additives. Finally, the analytical method was applied to emissions from two industries in the Modena (Italy) ceramic area. The results of all experimental phases were compared to those obtained by solid phase micro-extraction/gas chromatography/mass spectrometry (SPME/GC/MS). IMS showed potential as a real-time monitoring device for quality assessment in ceramic industry emissions. IMS spectra, SPME/GC/MS data, relationship between additives/baking conditions and produced VOCs and advantages and limitations of both techniques will be discussed.


Assuntos
Poluentes Atmosféricos/análise , Cerâmica , Compostos Orgânicos/análise , Monitoramento Ambiental , Resíduos Industriais , Espectrometria de Massas/métodos , Compostos Orgânicos/química
2.
Anal Chem ; 73(16): 3824-7, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11534703

RESUMO

Some improvements to the membrane introduction mass spectrometry (MIMS) technique, resulting in low-ppt detection limits for volatile organohalogen compounds (CX) in water (namely, chloroform, bromoform, bromodichloromethane, chlorodibromomethane, tetrachloroethylene, trichloroethylene, 1,1,1-trichloroethane, and carbon tetrachloride) and low-microgram per cubic meter detection limits for benzene, toluene, ethylbenzene, and xylenes (BTEX) in gaseous samples, are shown. A static MIMS configuration was compared to a dynamic one, the former requiring longer time to obtain the analytical response. A cryotrapping preconcentration step is introduced and linearity of response, mixture effects, and detection limits are presented. The instrumental setup consists of a hollow fiber silicone membrane, a water or air container, a cryofocusing trap based on Tenax adsorbent, a Peltier cell, and a Varian ion trap benchtop mass spectrometer is described. This instrumental setup, which we named membrane extraction trap focusing mass spectrometry, allowed the detection of CX in water at a concentration as low as 8 ppt and of benzene in air at 0.1 microg/m3. The whole assembly shows great potential for on-site routine monitoring of drinking water resources and urban and indoor air under current EU and Italian regulations.

3.
Rapid Commun Mass Spectrom ; 15(9): 665-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11319786

RESUMO

Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS) has been investigated as a tool for accurate determination of the molecular mass of synthetic analogues of prazosine, a molecule used for the treatment of hypertension. Samples were dissolved in methanol, mixed with mass calibration standards, and crystallised on the target with alpha-cyano-4-hydroxycinnamic acid as matrix. Acquisition of spectra was rapidly completed in reflectron mode, allowing high resolution (6000-10000) and sensitive (about 1-10 pmol of sample on target) determination of the synthetic products. The results show the effectiveness of MALDI-TOFMS for accurate mass determination of these fairly large molecules, which are otherwise difficult to analyse by other high-resolution mass spectrometric techniques.


Assuntos
Antagonistas Adrenérgicos alfa/análise , Prazosina/análogos & derivados , Prazosina/análise , Calibragem , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrofotometria Ultravioleta
4.
Rapid Commun Mass Spectrom ; 14(10): 905-10, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10825255

RESUMO

Some fractions of beer-factory wastewaters represent an important environmental concern owing to their high content of polyphenols and dark-brown color. The capacity of Coriolopsis gallica to preferentially degrade lignin has been successfully applied in our laboratory to the biotreatment and decolorization of paper-industry effluents. In this work, the ability of this white-rot fungus to degrade high-tannin-containing wastewaters is evaluated. Under all the conditions studied, effluent decolorization and chemical oxygen demand reduction achieved by C. gallica at day 12 of incubation were close to 50 and 65%, respectively. No adhesion of dark color to the fungal mycelium was observed suggesting that decolorization could be ascribed to C. gallica degradation systems. Mycelium dry-weight values showed that C. gallica is tolerant to relatively high tannin content present in the effluent samples. In the sample containing the highest effluent concentration (60% v/v), dry-weight values suggested an inhibition of fungal growth at day 6 of incubation and a further adaptation of the fungus to the stressing tannin effect at day 12 of fungal treatment. Pyrolysis/gas chromatography/mass spectrometry results showed a decrease of polyphenols pyrolysis products, mainly phenol and guaiacol, with the incubation time. All these results indicate the potential use of C. gallica in bioremediation of tannin-containing industrial wastewaters and in other applications where a reduction in polyphenols content is required.


Assuntos
Flavonoides , Cromatografia Gasosa-Espectrometria de Massas/métodos , Polyporales/metabolismo , Taninos/metabolismo , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/metabolismo , Cerveja , Biodegradação Ambiental , Fenóis/metabolismo , Polímeros/metabolismo , Polifenóis , Polyporales/crescimento & desenvolvimento
5.
Rapid Commun Mass Spectrom ; 13(20): 2049-53, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10510419

RESUMO

The analysis of organic pollutants in drinking water is a topic of wide interest, reflecting on public health and life quality. Many different methodologies have been developed and are currently employed in this context, but they often require a time-consuming sample pre-treatment. This step affects the recovery of the highly volatile compounds. Trace analysis of volatile organic pollutants in water can be performed 'on-line' by membrane inlet mass spectrometry (MIMS). In MIMS, the sample is separated from the vacuum of the mass spectrometer by a thin polymeric hollow-fibre membrane. Gases and organic volatile compounds diffuse and concentrate from the sample into the hollow-fibre membrane, and from there into the mass spectrometer. The main advantages of the technique are that no pre-treatment of samples before analysis is needed and that it has fast response times and on-line monitoring capabilities. This paper reports the set-up of the analytical conditions for the analysis of volatile organohalogen compounds (chloroform, bromoform, bromodichloromethane, chlorodibromomethane, tetrachloroethylene, trichloroethylene, 1,1,1-trichloroethane, and carbon tetrachloride). Linearity of response, repeatability, detection limits, and spectra quality are evaluated.


Assuntos
Hidrocarbonetos Halogenados/análise , Espectrometria de Massas/métodos , Poluentes da Água/análise , Água/química , Tetracloreto de Carbono/análise , Clorofórmio/análise , Hidrocarbonetos Bromados/análise , Controle de Qualidade , Reprodutibilidade dos Testes , Tetracloroetileno/análise , Tricloroetanos/análise , Tricloroetileno/análise , Trialometanos , Volatilização
6.
Rapid Commun Mass Spectrom ; 13(21): 2133-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10523771

RESUMO

In this work, a solid-phase microextraction (SPME) method for the extraction of volatile organic compounds (VOCs) from water samples has been developed. Fifty-five volatile compounds (from the sixty listed in EPA method no. 524.2) were extracted from aqueous solutions using an SPME fiber coated with Carboxen-polydimethylsiloxane (Carboxen-PDMS), 75 &mgr;m film thickness. Time of sampling and chromatographic separation conditions were optimised. Standard solutions of VOC mixtures with concentrations as low as 0.05 ppb were analysed and their signal/noise ratios measured. Linearity of response for each component of the mixture was tested and mass spectral quality evaluated. A comparison with purge and trap analysis of VOCs was made. The method was applied to real-world samples of drinking, surface and leaching waters. Copyright 1999 John Wiley & Sons, Ltd.

7.
Studi Emigr ; 34(126): 269-83, 1997 Jun.
Artigo em Italiano | MEDLINE | ID: mdl-12293096

RESUMO

PIP: "Between November 1995 and March 1996, Italy enacted a new programme for the regularization of foreigners in an irregular situation.... The programme had major consequences not only on foreign population size, since more than one million immigrants held residence permits at the end of 1996, but also on the labour market, by considerably reducing the illegal labour force.... The first part [of the essay] deals with legal provisions under which regularization could be granted, the success in combating illegal situations..., a comparison with previous regularization programmes and the geographical distribution of regularized immigrants. The second part analyses the specific relationship between regularization and labour market taking into account foreigners registered as unemployed, those employed under new contracts, and relevant percentages according to sectors of activity and regions. A final section is dedicated to the study of similarities and differences between present and past employment of foreign workers." (EXCERPT)^ieng


Assuntos
Emigração e Imigração , Emprego , Legislação como Assunto , Migrantes , Demografia , Países Desenvolvidos , Economia , Etnicidade , Europa (Continente) , Mão de Obra em Saúde , Itália , População , Características da População , Dinâmica Populacional
8.
Appl Environ Microbiol ; 62(6): 1928-34, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16535332

RESUMO

A brown material, precipitable with ethanol, was formed during wheat straw and lignin degradation by liquid cultures of different species of Pleurotus. Fourier transform infrared spectroscopy and cross-polarization and magic-angle-spinning (sup13)C nuclear magnetic resonance spectroscopy showed that most of the precipitable material was formed from exopolysaccharide secreted by the fungus but it also contained an aromatic fraction. The results of acid hydrolysis, methylation analysis, and Smith degradation indicated that the major exopolysaccharide produced by these fungi is a (1(symbl)3)-(beta)-glucan branched at C-6 every two or three residues along the main chain. The presence of lignin or straw in the culture medium had little effect on the composition and structure of the extracellular polysaccharide. Cross-polarization and magic-angle-spinning (sup13)C nuclear magnetic resonance spectroscopy provided an estimation of the aromatic content of the lignin-polysaccharide complexes, assigning 20% of the total (sup13)C signal in the material recovered from cultures of Pleurotus eryngii in lignin medium to aromatic carbon. Analytical pyrolysis indicated that the aromatic fractions of the lignin-polysaccharide complexes were derived from lignin, since products characteristic of pyrolytic breakdown of H (p-hydroxyphenylpropane), G (guaiacylpropane), and S (syringylpropane) lignin units were identified. These complexes cannot be fractionated by treatment with polyvinylpyrrolidone or extraction with lignin solvents, suggesting that the two polymers were chemically linked. Moreover, differences in composition with respect to the original lignin indicated that this macromolecule was modified by the fungi during the process of formation of the lignin-polysaccharide complexes.

9.
Anal Bioanal Chem ; 354(3): 381-3, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15048470

RESUMO

High performance liquid chromatography (HPLC) and gas chromatography (GC) were compared for the analysis of the amino acid composition in painting ligands.

10.
Rapid Commun Mass Spectrom ; 9(9): 815-26, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7655075

RESUMO

The use of pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) to determine the molecular composition of lignocellulose is reviewed and the technique illustrated with applications on some novel systems. Constituents and structural arrangement of lignocellulosic polymers in plant cell wall are briefly described. The basic principles of pyrolysis and the main advantages and disadvantages of PY/GC/MS are discussed. PY/GC/MS analyses of (a) paper industry effluents, (b) agricultural by-products subjected to biological processes of delignification and (c) recycled paper are presented as examples of the amount of information that PY/GC/MS can provide on lignin classification and monitoring of delignification treatments as well as on the fingerprinting of lignocellulosic materials. The ion trap detector mass spectra of 56 pyrolysis products of lignocellulose, including compounds of phenolic, furanic and pyranic nature, are shown.


Assuntos
Celulose/química , Lignina/química , Cromatografia Gasosa-Espectrometria de Massas , Indústrias , Papel , Esgotos/análise , Poluentes Químicos da Água
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