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Showing 1-30 of 57 results for "245917" within Papers
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
Zhanghao Chen et al.
Chemosphere, 235, 1180-1188 (2019-09-29)
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a class of highly persistent contaminants with high bioaccumulation and toxicity. Our previous studies showed that perfluorooctanoic acid (PFOA) can be completely defluorinated under UV irradiation in organo-montmorillonite/indole acetic acid (IAA) system. However, there
Péter Jankovics et al.
Journal of pharmaceutical and biomedical analysis, 112, 155-168 (2015-01-01)
The analysis of highly polar (often charged) compounds which lack a strong UV absorbing chromophore is really challenging. Despite the numerous analytical methods published, the demand for a simple, robust and cheap technique for their analysis still persists. Here, reversed
Kathrin Müller et al.
Analytical and bioanalytical chemistry, 412(20), 4867-4879 (2020-03-05)
Matrix effects have been shown to be very pronounced and highly variable in the analysis of mobile chemicals, which may severely exacerbate accurate quantification. These matrix effects, however, are still scarcely studied in combination with hydrophilic interaction liquid chromatography (HILIC)
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
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
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
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
Qian Chen et al.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 224, 117362-117362 (2019-07-29)
In this work, a novel strategy for perfluorooctane sulfonic acid (PFOS) detection was established by using a ratiometric nanosensor with the combination of fluorescence and second-order scattering (SOS). The practical ratiometric nanosensor was synthesized simply by mixing fluorescent dye ethidium
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
Estelle Dubreil et al.
Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment, 34(4), 453-468 (2016-09-03)
An approach is described to validate a fast and simple targeted screening method for antibiotic analysis in meat and aquaculture products by LC-MS/MS. The strategy of validation was applied for a panel of 75 antibiotics belonging to different families, i.e.
Fei Li et al.
Chemosphere, 200, 124-132 (2018-02-25)
The anaerobic biodegradability and metabolic pathways of 8:2 fluorotelomer alcohol (8:2 FTOH) were investigated in anaerobic activated sludge. The biodegradation was well described by a double exponential decay model. 8:2 FTOH was biodegraded to poly- and perfluorinated metabolites with the
Zhuyu Sun et al.
Chemosphere, 174, 127-135 (2017-02-06)
Perfluoroalkyl acids (PFAAs) have been found to be ubiquitously disseminated in the environment due to their widespread use in recent decades. In this study, the occurrence and spatiotemporal distribution of PFAAs in the surface water of Huangpu River, Shanghai, China
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
Imad A Haidar Ahmad et al.
Journal of chromatography. A, 1603, 1-7 (2019-06-15)
In recent years, charged aerosol detection (CAD) has become a valuable tool for fast and efficient quantitative chromatographic analysis of drug substances with weak UV absorption. In analytical method development using CAD, the power function settings available in the instrument
Nguyen Huu Hoang et al.
Journal of separation science, 39(24), 4712-4722 (2016-10-26)
A high-performance liquid chromatography with electrospray ionization ion trap tandem mass spectrometry method was developed and validated for the robust profiling and characterization of biosynthetic congeners in the 2-deoxy-aminocyclitol istamycin pathway, from the fermentation broth of Streptomyces tenjimariensis ATCC 31603.
Meng-Jia Chen et al.
Journal of hazardous materials, 303, 111-118 (2015-10-30)
Perfluorooctanoic acid (PFOA, C7H15COOH) is widely used in industrial and commercial applications. It has become a global concern due to its widespread occurrence in water bodies and adverse environmental impact. PFOA could not be effectively removed by the conventional UV/TiO2
Yu-Chi Lee et al.
Water research, 174, 115618-115618 (2020-02-24)
Using persulfate (PS) oxidation to remove the persistent perfluorooctanoic acid (PFOA) in water typically requires an elevated temperature or an extended reaction time. Under relatively ambient temperatures (15-45 °C), feasibility of employing PS with iron-modified activated carbon (AC) for PFOA oxidation
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
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
Synthesis of perfluoroalkyl thioethers from aromatic thiocyanates by iron-catalysed decarboxylative perfluoroalkylation
Exner, Benjamin and Bayarmagnai, Bilguun and Matheis, Christian and Goossen, Lukas J
Journal of Fluorine Chemistry, 198, 89-93 (2017)
Chunyu Yu et al.
Analytical and bioanalytical chemistry, 407(22), 6891-6897 (2015-07-04)
Polyamines and their N-acetylated metabolites are potential biomarkers in the diagnosis and therapeutic evaluation of cancer. Thus, we present here an ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of 6 free, 3 monoacetylated, and 2
Tae-Hun Kim et al.
The Science of the total environment, 631-632, 1295-1303 (2018-05-08)
Perfluorooctane sulfonate (PFOS) has been found in wastewater treatment plants (WWTPs) and in surface water as a result of domestic uses of textiles, electronics, and surfactants. The detection of PFOS in the aqueous environment has been linked to hazardous biological
Kun Lv et al.
Journal of hazardous materials, 392, 122354-122354 (2020-02-26)
In this study, a new phototransformation pathway for perfluorooctane sulfonamide (FOSA) and underlying degradation mechanisms are described. Phototransformation of FOSA in a natural clay mineral (montmorillonite) suspension was compared to that in an aqueous solution. Results showed that the presence
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
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
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
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
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
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