Results 101 to 110 of about 757 (137)

Interferences in the direct quantification of bisphenol S in paper by means of thermochemolysis

Journal of Chromatography A, 2013
This article analyses the interferences in the quantification of traces of bisphenol S in paper by applying the direct analytical method "analytical pyrolysis gas chromatography mass spectrometry" (Py-GC/MS) in conjunction with on-line derivatisation with tetramethylammonium hydroxide (TMAH). As the analytes are simultaneously analysed with the matrix,
Valentina, Becerra, Jürgen, Odermatt
openaire   +2 more sources

Characterization of peatified and coalified wood by tetramethylammonium hydroxide (TMAH) thermochemolysis

International Journal of Coal Geology, 1996
Abstract Seven samples of peatified and coalified wood, varying in rank from peat to subbituminous coal, have been analyzed using a new technique: thermochemolysis with tetramethylammonium hydroxide (TMAH). The preserved lignin in the coal undergoes thermochemolysis reactions when subjected to treatment with TMAH at 300°C for 10 min, yielding a ...
P G Hatcher
exaly   +2 more sources

Thermally assisted methylation of glycerol by tetramethylammonium hydroxide thermochemolysis

Journal of Analytical and Applied Pyrolysis, 2016
A novel method to rapidly methylate glycerol and generate products having greater value has been demonstrated using tetramethylammonium hydroxide (TMAH) thermochemolysis. Through analysis with GC–MS, it is shown that the reaction between TMAH and glycerol at elevated temperatures produces a series of mono, di and tri-methoxylated glycerols with ...
Derek C. Waggoner, Patrick G. Hatcher
openaire   +1 more source

Characterization of Estuarine and Fluvial Dissolved Organic Matter by Thermochemolysis using Tetramethylammonium Hydroxide [PDF]

Clean - Soil, Air, Water, 2000
Selected samples of dissolved organic matter (DOM) isolated by ultrafiltration (UDOM) have been analyzed by thermochemolysis in the presence of tetramethylammonium hydroxide (TMAH). This technique cleaves ester and ether bonds of bio- and geological macromolecules and releases monomer subunits and methylates them in situ as their methyl ethers and ...
José C del Río, P G Hatcher, J W de Leeuw   +2 more
exaly   +3 more sources

Comparison of reagents for off-line thermochemolysis of natural organic matter

Organic Geochemistry, 2004
Abstract A range of tetramethylammonium salts with different base strengths was compared for off-line thermochemolysis of an aquatic natural organic matter sample. Tetramethylammonium acetate (TMAAc) in methanol produced a different suite of compounds to the more alkaline tetramethylammonium hydroxide (TMAH) in methanol and tetramethylammonium ...
Cynthia A Joll, Daniel Couton, Anna Heitz, Robert I Kagi   +3 more
openaire   +1 more source

Analysis of structurally modified polyacrylamides by on-line thermochemolysis-GC–MS

Journal of Analytical and Applied Pyrolysis, 2007
Abstract Cationically modified polyacrylamides (cPAA) are commonly used flocculants in sewage water treatment processes. Therefore, those compounds are quantitatively important contaminants in sewage sludges, which were deposited on agricultural soils as fertilizers in the past and even today in many countries.
Alexander Kronimus, Jan Schwarzbauer
openaire   +1 more source

Tetramethylammonium hydroxide thermochemolysis of guaiacyl–syringyl and guaiacyl dehydrogenation polymers

Organic Geochemistry, 2005
Abstract Tetramethylammonium hydroxide thermochemolysis of lignin was investigated using guaiacyl–syringyl and guaiacyl dehydrogenation polymers. The guaiacyl–syringyl mixed polymer provided: (1) 1-(3,4-dimethoxyphenyl)-1,2,3-trimethoxypropane isomers ( 11 / 12 ) and 1-(3,4,5-trimethoxyphenyl)-1,2,3-trimethoxypropane isomers ( 15 / 16 ) as β-aryl ...
Ken-ichi Kuroda, Akiko Nakagawa-izumi
openaire   +1 more source

Electrophile tocopheryl quinones in apoptosis and mutagenesis: Thermochemolysis of thiol adducts with proteins and in cells

Lipids, 2003
AbstractElectrophile tocopheryl quinones from the phenolic antioxidants γ‐tocopherol and δ‐tocopherol form Michael adducts with the thiol nucleophile glutathione. These tocopheryl quinones are involved in cytotoxicity, apoptosis, and mutagenesis, and their biologic properties are associated with the depletion of intracellular thiols.
David G, Cornwell, Sunghwan, Kim, Paula A, Mazzer, Kenneth H, Jones, Patrick G, Hatcher   +4 more
openaire   +2 more sources

Tetramethylammonium hydroxide (TMAH) thermochemolysis of the aliphatic biopolymer cutan: insights into the chemical structure

Organic Geochemistry, 1996
Tetramethylammonium hydroxide (TMAH) thermochemolysis has been applied to the diagenetically resistant aliphatic biopolymer cutan derived from the leaf cuticles of Agave americana. Data obtained from the cutan sample using this new analytical method are vastly different in comparison with conventional flash pyrolysis data of the same sample.
P G Hatcher, J W de Leeuw
exaly   +2 more sources

Thermochemolysis of winery wastewater particulates—Molecular structural implications for water reuse

Journal of Analytical and Applied Pyrolysis, 2012
Abstract Environmental concerns have increased the interest in winery wastewater remediation and reuse. These practices require more detailed understanding of wastewater composition to ensure optimum usage, and to minimize the risk of long term soil degradation and grape contamination.
Mosse, K., Verheyen, T., Cruickshank, A., Patti, A., Cavagnaro, T.   +4 more
openaire   +2 more sources