Showing 1-27 of 27 results for "381721"
T Krishnamurthy et al.
Journal of chromatography, 355(1), 253-264 (1986-03-14)
The pentafluoropropionyl, (PFP) and trifluoroacetyl (TFA) esters of several naturally occurring and synthetically modified simple trichothecenes were synthesized in nanogram amounts and characterized. Optimum conditions for the gas chromatographic (GC) separation of these derivatives and their analysis by negative ion...
M Takino et al.
Journal of chromatography. A, 862(2), 191-197 (1999-12-22)
Anatoxin-a is a toxin produced from cyanobacterial blooms in freshwaters. In order to determine trace anatoxin-a in freshwaters, an automated on-line derivatization procedure with fluorenyl methylchloroformate using liquid chromatography-electrospray ionization mass spectrometry was developed. Anatoxin-a was extracted using solid-phase extraction...
David S Bell et al.
Journal of chromatography. A, 1095(1-2), 113-118 (2005-11-09)
Fluorinated, silica-based stationary phases are becoming increasingly popular alternatives to traditional alkyl phases owing to their differential selectivity and retention for a variety of analyte classes. In this report, the ion-exchange mechanisms characteristic of a fluorinated phase are exploited to...
Mohamed Osman Awaleh et al.
Inorganic chemistry, 46(8), 3185-3191 (2007-03-17)
Two topologically comparable complexes, [Ag6(CF3CO2)3(L1-Me)3(SCH3)3]infinity (1) and [Ag6(CF3CF2CO2)3(L1-Me)2(SCH3)3(H2O)]infinity (2), were prepared and characterized by single-crystal diffractometry. The structures consist of Ag12S6 clusters linked by bis(methylthio)methane ligands, L1-Me, thus forming 1D coordination polymers. The 12 Ag atoms of the cluster are...
K F Faull et al.
Journal of neuroscience research, 27(4), 533-540 (1990-12-01)
In experimental protocols with humans and non-human primates, cerebrospinal fluid (CSF) concentrations of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG), the predominant end-product of norepinephrine metabolism in the mammalian central nervous system (CNS), have been widely used as an index of the rate of...
G Skarping et al.
Journal of chromatography. A, 663(2), 199-210 (1994-03-11)
The determination of 2,3-, 3,4-, 2,6-, 2,4- and 2,5-toluenediamine (TDA) in hydrolysed human urine and blood plasma was studied by GC-MS. The TDA isomers as their perfluoro-fatty acid anhydride derivatives were investigated. Chemical ionization with ammonia and isobutane as reagent...
Atmospheric pressure deposition of fluorine-doped SnO2 thin films from organotin fluorocarboxylate precursors.
Mahon MF, et al.
Applied Organometallic Chemistry, 19(5), 658-671 (2005)
C W Tsang et al.
Biochemical and biophysical research communications, 165(3), 1331-1336 (1989-12-29)
The occurrence of 5-methoxytryptophol (5-MTL) in the quail retina was investigated by capillary column gas chromatography/mass spectrometry/selected ion monitoring using a deuterated internal standard. Based on ion intensity ratios in the mass spectra of pentafluoropropionyl and heptafluorobutyryl derivatives of 5-MTL...
New fluoro intermediates for herbicidal sulfonylureas.
Hamprecht G, et al.
Pestic. Sci., 55(5), 566-570 (1999)
Asa Marand et al.
The Analyst, 129(6), 522-528 (2004-05-21)
Determination of amines in biological samples as markers of exposure to the amines or the corresponding isocyanates is an important tool for industrial exposure assessment. In this study, a liquid chromatography and tandem mass spectrometry (LC-MS/MS) method for determination of...
M H Choi et al.
Journal of chromatography. A, 897(1-2), 295-305 (2000-12-29)
An efficient method is described for the simultaneous determination of hair polyamines, such as 1,3-diaminopropane, putrescine, cadaverine, spermidine and spermine, by gas chromatography-mass spectrometry (GC-MS) with the selected ion-monitoring (SIM) mode. The method is based on the extractive two-phase ethoxycarbonyl...
C Legrand et al.
Journal of chromatography. B, Biomedical applications, 663(2), 187-192 (1995-01-20)
Plasma testosterone was measured by gas chromatography-negative-ion chemical ionisation mass spectrometry (GC-MS). The testosterone was extracted from plasma using home-made Extrelut columns and diethyl ether elution. It was quantified as the pentafluoropropionate (PFP) derivative by selected-ion monitoring at m/z 560...
Vicky Manyanga et al.
Journal of chromatography. A, 1189(1-2), 347-354 (2008-01-18)
The official method for the determination of the composition and related substances of gentamicin prescribed by the European Pharmacopoeia (Ph. Eur.) is liquid chromatography combined with pulsed electrochemical detection (LC-PED). However, this method utilizes a polymer stationary phase which shows...
H B Lee et al.
Journal of AOAC International, 81(6), 1209-1216 (1998-12-16)
The paper describes a simple and quantitative method for monitoring non-conjugated 17 beta-estradiol (E2) and its metabolites estrone (E1) and estriol (E3) as environmental contaminants in municipal sewage effluents. Estrogens were preconcentrated and cleaned up by solid-phase extraction using a...
Maki Takatani et al.
Carbohydrate research, 338(10), 1073-1081 (2003-04-23)
Pentafluoropropionyl (PFP) and trifluoroacetyl (TFA) esters were demonstrated to be useful in facile oligosaccharide synthesis. These were well compatible with glycosylation conditions and removable by treatment with pyridine-EtOH, with complete preservation of acetyl groups. Analytically pure products were obtained quantitatively...
B Li et al.
Journal of pharmaceutical and biomedical analysis, 55(1), 78-84 (2011-02-15)
Liquid chromatography combined with pulsed electrochemical detection (LC-PED) is the method of choice in the European Pharmacopoeia for the determination of gentamicin and its related substances. A recently approved improved LC-PED method, with a reversed-phase C(18) column and a mobile...
[Recent development of C-terminal sequence analysis of proteins].
A Tsugita
Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme, 43(7), 857-865 (1998-06-23)
Sandra Rinne et al.
Journal of chromatography. A, 1119(1-2), 285-293 (2006-03-21)
A fast and sensitive capillary liquid chromatography (cLC) column-switching method with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) detection for the simultaneous determination of dopamine (D), epinephrine (E), norepinephrine (NE) and serotonin (SE) was pursued. A sample volume of 100 microl...
Clare Ho et al.
Journal of chromatography. A, 1235, 103-114 (2012-03-20)
Morantel, pyrantel and their drug-related metabolites in food of animal-origin are regulated as sum of residues which may be hydrolysed to N-methyl-1,3-propanediamine (NMPA). In this study, an isotope dilution liquid chromatography tandem mass spectrometry (LC-MS/MS) method with pentafluoropropionic acid anhydride...
Vicky Manyanga et al.
Journal of pharmaceutical and biomedical analysis, 45(2), 257-262 (2007-08-21)
Several liquid chromatographic (LC) methods have been described for the analysis of gentamicin. LC combined with pulsed electrochemical detection (LC-PED) or evaporative light scattering detection (LC-ELSD) was found to be the most suitable technique. A first method, previously developed by...
C T Mant et al.
Journal of chromatography. A, 1125(2), 211-219 (2006-07-04)
The present study set out to investigate whether observed relative hydrophilicity/hydrophobicity values of positively charged side-chains (with Lys and Arg as representative side-chains) or hydrophobic side-chains (with Ile as the representative side-chain) were context-dependent, i.e., did such measured values vary...
A Tsugita et al.
European journal of biochemistry, 206(3), 691-696 (1992-06-15)
Peptides or proteins were hydrolyzed by vapors of 90% pentafluoropropionic acid or heptafluorobutyric acid at 90 degrees C for various time periods. The hydrolyzate mixtures analyzed by both fast-atom-bombardment and electrospray ionization mass spectrometry showed a series of C-terminal successive...
J Flieger
Journal of chromatography. A, 1217(4), 540-549 (2009-12-09)
The addition of the homologous series of perfluorinated acids-trifluoroacetic acid (TFAA), pentafluoropropionic acid (PFPA), heptafluorobutyric acid (HFBA) to mobile phases for reversed-phase high-performance liquid chromatography (RP-HPLC) of beta-blockers was tested. Acidic modifiers were responsible for acidification of mobile phase (pH...
Sabina Strano-Rossi et al.
Journal of applied toxicology : JAT, 31(7), 649-654 (2010-12-07)
A rapid and sensitive method for the simultaneous determination of alfentanyl, sufentanyl and fentanyl (and its major metabolite norfentanyl) in urine was developed and validated. The method involved a liquid-liquid extraction in alkaline conditions, derivatization with pentafluoropropionic anhydride to improve...
Derek A Jackson et al.
Environmental science & technology, 45(19), 8030-8036 (2011-04-07)
Perfluorinated carboxylic acids are widely distributed in the environment, including remote regions, but their sources are not well understood. Perfluoropropionic acid (PFPrA, CF(3)CF(2)C(O)OH) has been observed in rainwater but the observed amounts can not be explained by currently known degradation...
Wenche Langseth et al.
Rapid communications in mass spectrometry : RCM, 24(17), 2641-2649 (2010-08-27)
This paper reports the mass spectra, obtained after electron ionisation (EI) at 70 eV, of 34 trichothecenes and five culmorin compounds after acylation with pentafluoropropionic anhydride. The derivatised fungal metabolites were separated by gas chromatography, and the mass spectra were...
Ralf Dillert et al.
Chemosphere, 67(4), 785-792 (2006-11-28)
The UV-photon-induced degradation of heptafluorobutanoic acid was investigated in acidic aqueous solutions in the presence of titanium dioxide. Heptafluorobutanoic acid could be degraded with this photocatalyst in a light-induced reaction generating carbon dioxide and fluoride anions. Carbon dioxide evolution in...

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