Phenols mass spectrometry

The comparison of the peat and wood flash pyrolysis products by Elliott ( ) is a good example of the effect of feedstock on product oil composition. The poplar oil typically was composed of phenolic, ketone and furan compounds with a substantial fraction of low molecular weight organic acids. The main components of the peat oil were hydrocarbons, mostly straight chain olefins. Minor quantities of ketones were noted but no acids, aldehydes or furans were identified by mass spectrometry. Phenols were also present in significant quantities. 

Organic admixtures in LCP were searched by mass-spectrometry. Phenol and dihydroxydiphenyloxide (the product of the dihydroxydiphenylacetate hydrolysis, m/e 94, 186) as well as the following fragments with higher molecular weight were identified. 

Mass Spectrometry A peak for the molecular ion is usually quite prominent m the mass spectra of phenols It is for example the most intense peak m phenol... 

The molecular weights and molecular weight distributions (MWD) of phenolic oligomers have been evaluated using gel permeation chromatography (GPC),23,24 NMR spectroscopy,25 vapor pressure osmometry (VPO),26 intrinsic viscosity,27 and more recently matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).28... 

Figure 5.46 Product-ion spectra of (a) Bosentan (1) [M -F H] 552.1917, and its (b) hydroxy metabolite (2) [M + H]+ 568.1866, (c) phenol metabolite (3) [M + H] 538.1760, and (d) hydroxyphenol metabolite (4) [M-FH] 554.1790. Reprinted by permission of Elsevier Science from Exact mass measurement of product ions for the structural elucidation of drug metabolites with a tandem quadrupole orthogonal-acceleration time-of-flight mass spectrometer , by Hopfgartner, G., Chemushevich, I. V., Covey, T., Plomley, J. B. andBonner, K., Journal of the American Society for Mass Spectrometry, Vo. 10, pp. 1305-1314, Copyright 1999 by the American Society for Mass Spectrometry.

Thermal properties of several chlorinated phenols and derivatives were studied by differential thermal analysis and mass spectrometry and in bulk reactions. Conditions which might facilitate the formation of stable dioxins were emphasized. No two chlorinated phenols behaved alike. For a given compound the decomposition temperature and rate as well as the product distribution varied considerably with reaction conditions. The phenols themselves seem to pyro-lyze under equilibrium conditions slowly above 250°C. For their alkali salts the onset of decomposition is sharp and around 350°C. The reaction itself is exothermic. Preliminary results indicate that heavy ions such as cupric ion may decrease the decomposition temperature. 

Knowledge of the identity of phenolic compounds in food facilitates the analysis and discussion of potential antioxidant effects. Thus studies of phenolic compounds as antioxidants in food should usually by accompanied by the identification and quantification of the phenols. Reversed-phase HPLC combined with UV-VIS or electrochemical detection is the most common method for quantification of individual flavonoids and phenolic acids in foods (Merken and Beecher, 2000 Mattila and Kumpulainen, 2002), whereas HPLC combined with mass spectrometry has been used for identification of phenolic compounds (Justesen et al, 1998). Normal-phase HPLC combined with mass spectrometry has been used to identify monomeric and dimeric proanthocyanidins (Lazarus et al, 1999). Flavonoids are usually quantified as aglycones by HPLC, and samples containing flavonoid glycosides are therefore hydrolysed before analysis (Nuutila et al, 2002). 

Hvattum, E., Determination of phenolic compounds in rose hip (Rosa canina) using liquid chromatography coupled to electrospray ionisation tandem mass spectrometry and diode-array detection, Rapid Commun. Mass Spectrom., 16, 655, 2002. 

Kohler M, NV Heeb (2003) Determination of nitrated phenolic compounds in rain by liquid chromatography/ atmospheric pressure chemical ionization mass spectrometry. Anal Chem 75 3115-3121. 

In an acetone extract from a neoprene/SBR hose compound, Lattimer et al. [92] distinguished dioctylph-thalate (m/z 390), di(r-octyl)diphenylamine (m/z 393), 1,3,5-tris(3,5-di-f-butyl-4-hydroxybenzyl)-isocyanurate m/z 783), hydrocarbon oil and a paraffin wax (numerous molecular ions in the m/z range of 200-500) by means of FD-MS. Since cross-linked rubbers are insoluble, more complex extraction procedures must be carried out (Chapter 2). The method of Dinsmore and Smith [257], or a modification thereof, is normally used. Mass spectrometry (and other analytical techniques) is then used to characterise the various rubber fractions. The mass-spectral identification of numerous antioxidants (hindered phenols and aromatic amines, e.g. phenyl-/ -naphthyl-amine, 6-dodecyl-2,2,4-trimethyl-l,2-dihydroquinoline, butylated bisphenol-A, HPPD, poly-TMDQ, di-(t-octyl)diphenylamine) in rubber extracts by means of direct probe EI-MS with programmed heating, has been reported [252]. The main problem reported consisted of the numerous ions arising from hydrocarbon oil in the recipe. In older work, mass spectrometry has been used to qualitatively identify volatile AOs in sheet samples of SBR and rubber-type vulcanisates after extraction of the polymer with acetone [51,246]. 

Samaras VG, Thomaidis NS, Stasinakis AS, Lekkas TD (2011) An analytical method for the simultaneous trace determination of acidic pharmaceuticals and phenolic endocrine disrupting chemicals in wastewater and sewage sludge by gas chromatography-mass spectrometry. Anal Bioanal Chem 399 2549-2561... 

Y.Y. Soong and P.J. Barlow, Isolation and structure elucidation of phenolic compounds from longan (Dimocarpus longan Lour.) seed by high performance liquid chromatography electrospray ionization mass spectrometry, J. Chromatogr. A, 1085, 270 277 (2005). 

Canini A, Alesiani D, D Arcangelo G and Tagliatesta P. 2007. Gas chromatography-mass spectrometry analysis of phenolic compounds from Carica papaya L. leaf. J Food Comp Anal 20 584-590. 

Over the past two decades, capillary electrophoresis (CE) and related techniques have rapidly developed for the separation of a wide range of analytes, ranging from large protein molecules to small inorganic ions. Gas chromatography has been considered as a powerful tool due to its sensitivity and selectivity, especially when coupled with mass spectrometry. Nevertheless, liquid chromatography is the most used method to separate and analyze phenolic compounds in plant and tissue samples. 

Mass spectrometry applied to characterization of phenolic compounds has been widely reviewed (Fulcrand and others 2008 Harnly and others 2007 de Rijke and others 2006 Prasain and others 2004). Therefore, here we describe the most common mass spectroscopic methods used for the analysis of phenolic compounds. 

Huck WC, Stecher G, Scherz H and Bonn G. 2005. Analysis of drugs, natural and bioactive compounds containing phenolic groups by capillary electrophoresis coupled to mass spectrometry. Electrophoresis 26(7-8) 1319-1333. 

Im HW, Suh BS, Lee SU, Kozukue N, Ohnisi-Kameyama M, Levin CE and Friedman M. 2008. Analysis of phenolic compounds by high-performance liquid chromatography and liquid chromatography/mass spectrometry in potato plant flowers, leaves, stems, and tubers and in home-processed potatoes. J Agric Food Chem 56(9) 3341-3349. 

Lafont F, Aramendia M, Garcia I, Borau V, Jimenez C, Marinas JM and Urbano F. 1999. Analyses of phenolic compounds by capillary electrophoresis electrospray mass spectrometry. Rapid Commun Mass Spectrom 13(7) 562-567. 

Boyd [148] determined ppq levels of phenols, cresols, and catechols in San Diego Bay (CA, USA) water by aqueous acetylation of the sample followed by gas chromatography-mass spectrometry. 

Reversed phase liquid chromatography-mass spectrometry was applied to extracts of Jamaica Bay (New York) water to determine 1-300 xg/l amounts of nonyl phenol ethoxylates and their metabolites [213]. 

L6pez-Roldan P., de Alda M.J.L., and Barcelo D., 2004. Simultaneous determination of selected endocrine disrupters (pesticides, phenols and phthalates) in water by in-field solid-phase extraction (SPE) using the prototype PROFEXS followed by online SPE (PROSPEKT) and analysis by liquid chromatography-atomspheric pressure chemical ionization-mass spectrometry. Anal Bioanal Chem 378 599. 

Wissiack R., Rosenberg E., and Grasserbauer M., 2000. Comparison of different sorbent materials for online solid-phase extraction with liquid chromatography-atmospheric pressure chemical ionization mass spectrometry of phenols. J Chromatogr B 896 159. 

Liquid chromatography-(tandem) mass spectrometry of selected emerging pollutants (steroid sex hormones, drugs and alkyl phenolic surfactants) in the aquatic environment [56]... 

Karasek et al. [6] determined phenols in soils by extraction with a mixture of benzene and water modified to pHIO by the addition of 2-methoxyethylamine. The phenol in the extract was identified and determined by gas chromatography using a variety of detectors including flame ionization, electron capture and mass spectrometry. 

S. Perez-Magarino, I. Revilla, M.L. Gonzalez-SanJose and S.Beltran, Various applications of liquid chromatography-mass spectrometry to the analysis of phenolic compounds. J. Chromatogr.A, 847 (1999)75-81. 

Puig et al. [450] determined ng/1 levels of priority methyl-, nitro-, and chloro-phenols in river water samples by an automated on-line SPE technique, followed by liquid chromatography-mass spectrometry (LC-MS) using atmospheric pressure chemical ionization (APCI) and ion spray interfaces. 

Capillary columns may provide the best method for the separation of phenols prior to their quantification (Eichelberger et al. 1983 Shafer et al. 1981 Sithole et al. 1986). Of the various methods available for detection, the two commonly used methods that are most sensitive are mass spectrometry and flame ionization detection. Although electron capture detectors provide good sensitivities for higher chlorine-substituted phenols, they are poor for phenol itself (Sithole et al. 1986). The best method for the quantification of phenol may be mass spectrometric detection in the selected ion mode, but the loss of qualitative information may be significant (Eichelberger et al. 1983). 

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