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Anne Scheyer et al.
Analytical and bioanalytical chemistry, 387(1), 359-368 (2006-11-15)
Solid-phase microextraction (SPME) was used for the analysis of some pesticides (bromoxynil, chlorotoluron, diuron, isoproturon, 2,4-MCPA, MCPP and 2,4-D) in rainwater after derivatisation with PFBBr and gas chromatography-ion trap mass spectrometry. The derivatisation procedure was optimized by testing different methods:
Jingyuan Sun et al.
Journal of experimental & clinical cancer research : CR, 39(1), 222-222 (2020-10-23)
Radioresistance is the major obstacle in radiation therapy (RT) for hepatocellular carcinoma (HCC). Dysregulation of DNA damage response (DDR), which includes DNA repair and cell cycle checkpoints activation, leads to radioresistance and limits radiotherapy efficacy in HCC patients. However, the
Laura Mateo-Vivaracho et al.
Journal of chromatography. A, 1121(1), 1-9 (2006-05-09)
A fast and automated method for the analysis at ng L(-1) level of aroma-powerful polyfunctional thiols has been developed and applied to wine. The sample is just poured in a 20 mL vial and its vapour extracted with a poly(dimethylsiloxane)-divinylbenzene
Guang-Wen Lien et al.
Journal of chromatography. A, 1216(6), 956-966 (2009-01-03)
This study compared the sensitivities and matrix effects of four ionization modes and four reversed-phase liquid chromatographic (LC) systems on analyzing estrone (E1), 17beta-estradiol (E2), estriol (E3), 17alpha-ethinylestradiol (EE2), 4-nonylphenol (NP), 4-tert-octylphenol (OP), bisphenol A (BPA) and their derivatives of
Lei Zhang et al.
Journal of chromatography. A, 1074(1-2), 1-7 (2005-06-09)
A method for determination of thyreostatic residues in animal tissues by matrix solid-phase dispersion (MSPD) and gas chromatography-mass spectrometry in selected ion detection mode was developed. Thyreostatic compounds in different matrices were extracted and purified by combination of MSPD and
Arne Trettin et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 964, 172-179 (2014-02-11)
Oleic acid (cis-9,10-octadecenoic acid) is the most abundant monounsaturated fatty acid in human blood. Peroxynitrite (ONOO(-)) is a short-lived species formed from the reaction of nitric oxide (NO) and superoxide (O2(-)). Peroxynitrite is a potent oxidizing and moderate nitrating agent.
Dimitrios Tsikas et al.
Analytical chemistry, 82(19), 7897-7905 (2010-06-18)
Carbon dioxide and carbonates are widely distributed in nature, are constituents of inorganic and organic matter, and are essential in vegetable and animal organisms. CO(2) is the principal greenhouse gas in the atmosphere. In human blood, CO(2)/HCO(3)(-) is an important
Dimitrios Tsikas
The Analyst, 136(5), 979-987 (2010-12-22)
Nitric oxide (˙NO) and superoxide (O(2)(-)˙) are ubiquitous in nature. Their reaction product peroxynitrite (ONOO(-)) and notably its conjugated peroxynitrous acid (ONOOH) are highly unstable in aqueous phase. ONOO(-)/ONOOH (referred to as peroxynitrite) isomerize and decompose to NO(3)(-), NO(2)(-) and
Stephanie L Youso et al.
Analytica chimica acta, 677(1), 24-28 (2010-09-21)
Exposure to cyanide can occur in a variety of ways, including exposure to smoke from cigarettes or fires, accidental exposure during industrial processes, and exposure from the use of cyanide as a poison or chemical warfare agent. Confirmation of cyanide
Anne Scheyer et al.
Analytical and bioanalytical chemistry, 381(6), 1226-1233 (2005-03-26)
A multiresidue method using gas chromatography coupled to ion-trap tandem mass spectrometry (MS/MS) was developed for the analysis of 27 pesticides, commonly used in Alsace, in atmospheric samples (particle and gas phases). As pesticides are expected to be present at
Jim T Yu et al.
Analytical and bioanalytical chemistry, 403(2), 583-591 (2012-03-01)
A sensitive yet robust analytical method is presented for the simultaneous determination of 12 human pharmaceuticals (valproic acid, phenytoin, ibuprofen, gabapentin, acetaminophen, gemfibrozil, naproxen, ketoprofen, secobarbital, phenobarbital, 5-fluorouracil, and diclofenac) and 6 antiseptics (biosol, biphenylol, p-chloro-m-cresol, p-chloro-m-xylenol, chlorophene, and triclosan).
F A Tarbah et al.
Journal of analytical toxicology, 28(3), 198-203 (2004-04-27)
Many organophosphate pesticides (OP) such as phosphamidon are unstable in aqueous solutions and especially in blood in the presence of esterases. In a case of intoxication, the phosphamidon concentration in serum decreased from 10 mg/L to 4.4 mg/L after storage
Laura Mateo-Vivaracho et al.
Journal of chromatography. A, 1146(2), 242-250 (2007-02-24)
A fast method for the determination of aroma-powerful polyfunctional thiols at nanogram per liter level has been developed and applied to wine. A small volume of wine (6 mL) was extracted with 1.5 mL of benzene containing four internal standards.
D H Fisher et al.
Journal of chromatography, 452, 51-60 (1988-10-28)
The following sequence of analytical steps was used to determine the amount of 5-methylcytosine (mol-%) in calf thymus and human lymphocyte DNA:acid hydrolysis of the DNA, derivatization (pentafluorobenzyl bromide, solid phase extraction, pivalic anhydride), internal standard addition, solid phase extraction
Yoshifumi Hanada et al.
Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 18(6), 655-659 (2002-06-27)
An analytical method using pentafluorobenzyl bromide (PFBB) derivatization and gas chromatography/mass spectrometry (GC/MS) has been applied to identify and quantify chloro-, bromo- and dichlorophenols in air, water and sediment samples. Phenols in air sample were collected with a PS-2 Sep-PAK
Arne Trettin et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 966, 171-178 (2013-12-25)
Paracetamol (acetaminophen, APAP) is a commonly used analgesic drug. Known paracetamol metabolites include the glucuronide, sulfate and mercapturate. N-Acetyl-benzoquinonimine (NAPQI) is considered the toxic intermediate metabolite of paracetamol. In vitro and in vivo studies indicate that paracetamol is also metabolized
Laura Mateo-Vivaracho et al.
Journal of chromatography. A, 1185(1), 9-18 (2008-02-09)
A fast method for the determination of aroma-powerful polyfunctional thiols at ng L(-1) level has been developed. Mercaptans are selectively retained in a 50mg solid-phase extraction cartridge and derivatization takes place in the same cartridge at room temperature (25 degrees
Alexander A Zoerner et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 879(17-18), 1444-1456 (2010-07-20)
In the human body, the catecholamine norepinephrine is mainly metabolized to 3,4-dihydroxyphenylglycol (DHPG) which therefore serves as an important biomarker for norepinephrine's metabolism. Most data on DHPG concentrations in human plasma and urine has been generated by using HPLC-ECD or
Yan Li et al.
Frontiers in bioengineering and biotechnology, 7, 394-394 (2019-12-24)
The main challenges in multienzymatic cascade reactions for CO2 reduction are the low CO2 solubility in water, the adjustment of substrate channeling, and the regeneration of co-factor. In this study, metal-organic frameworks (MOFs) were prepared as adsorbents for the storage
Arne Trettin et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 959, 71-81 (2014-04-29)
Paracetamol (acetaminophen) is a widely used safe analgesic drug when administered at therapeutic doses. Given the chemical reactivity of its phenolic group towards electrophilic species, we assumed that detection of paracetamol metabolites distinctly different from its known phase I metabolite
Anke Böhmer et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 965, 173-182 (2014-07-18)
In healthy human subjects, less than 0.2% of l-arginine is converted to l-citrulline and nitric oxide (NO) by NO synthases (NOS), a metabolic pathway present in all cell types. Assessment of NOS activity in vitro and in vivo by measuring
Aikaterini S Chajistamatiou et al.
Talanta, 195, 456-462 (2019-01-11)
Black Powder (BP) is one of the most common improvised explosives, due to broad access in precursors and simple home-made preparation. Deflagration of black powder results in residues the chemical analysis of which presents limitations and has been performed with
Anja Mitschke et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 851(1-2), 287-291 (2007-03-14)
The nitrated lipids 9-nitro-oleic acid (9-NO(2)-OA) and 10-nitro-oleic acid (10-NO(2)-OA) have been reported to be present in blood of healthy humans. Free and esterified forms of 9-NO(2)-OA and 10-NO(2)-OA have been detected in human plasma at about 600 and 300
Measurement of 8-epi-PGF2alpha as a marker of lipid peroxidation in vivo by immunoaffinity extraction and gas chromatography-mass spectrometry.
Nitin K Gopaul et al.
Methods in molecular biology (Clifton, N.J.), 225, 329-342 (2003-05-29)
Hauh-Jyun Candy Chen et al.
Toxicology letters, 155(3), 403-410 (2005-01-15)
5-Hydroxymethyluracil (5-HMU) is derived from radiation in addition to endogenous oxidative DNA damage and it is one of the most abundant DNA adducts. Human 5-HMU-DNA-glycosylase has been shown to repair this lesion. Whether urinary levels of 5-HMU is a valid
Minghong Jia et al.
Analytical chemistry, 75(16), 4065-4080 (2003-11-25)
Haloacetic acids (HAAs) are environmentally and medically important chemicals. No analytical method is currently available to analyze EPA-regulated HAAs in biological samples at environmentally relevant low concentrations. Clinical studies of this class of chemicals are also limited by the lack
Bilal N Sheikh et al.
Nature cell biology, 22(7), 828-841 (2020-06-17)
Mutations in chromatin-modifying complexes and metabolic enzymes commonly underlie complex human developmental syndromes affecting multiple organs. A major challenge is to determine how disease-causing genetic lesions cause deregulation of homeostasis in unique cell types. Here we show that neural-specific depletion
Dimitrios Tsikas et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 879(17-18), 1476-1484 (2011-03-01)
Pentafluorobenzyl (PFB) bromide (PFB-Br) is a versatile derivatization reagent for numerous classes of compounds. Under electron-capture negative-ion chemical ionization (ECNICI) conditions PFB derivatives of acidic compounds readily and abundantly ionize to produce intense anions due to [M-PFB](-). In the present
Dimitrios Tsikas
Methods in molecular biology (Clifton, N.J.), 279, 81-103 (2004-06-17)
Measurement of the nitric oxide (NO) metabolites nitrite and nitrate in biological matrices is a reliable method to assess NO synthase (NOS) activity. Unlike the "L-citrulline assay," the "nitrite/nitrate assay" is generally applicable and permits acquisition of maximum information about
Valdemir Melechco Carvalho et al.
Analytical biochemistry, 381(1), 67-73 (2008-07-12)
Despite the new advances in bioanalytical techniques, the analysis of low-molecular-weight organic acids in complex matrices is still a challenge. Although new strategies applying liquid chromatography-tandem mass spectrometry (LC-MS/MS) seem to be promising, sample preparation methodologies hamper its application in
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