101052

应用筛选条件

关键词:'101052'

显示 1-30 共 38 条结果关于 "101052" 范围论文

Determination of cyanide exposure by gas chromatography-mass spectrometry analysis of cyanide-exposed plasma proteins.

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

Application of a pentafluorobenzyl bromide derivatization method in gas chromatography/mass spectrometry of trace levels of halogenated phenols in air, water and sediment samples.

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

Determination of 5-methylcytosine in DNA by gas chromatography-electron-capture detection.

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

Acute poisoning with phosphamidon: determination of dimethyl phosphate (DMP) as a stable metabolite in a case of organophosphate insecticide intoxication.

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

Quantitative determination of wine polyfunctional mercaptans at nanogram per liter level by gas chromatography-negative ion mass spectrometric analysis of their pentafluorobenzyl derivatives.

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.

UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation.

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

A multiresidue method using ion-trap gas chromatography-tandem mass spectrometry with or without derivatisation with pentafluorobenzylbromide for the analysis of pesticides in the atmosphere.

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

Determination of pharmaceuticals and antiseptics in water by solid-phase extraction and gas chromatography/mass spectrometry: analysis via pentafluorobenzylation and stable isotope dilution.

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).

GC-MS and HPLC methods for peroxynitrite (ONOO- and O15NOO-) analysis: a study on stability, decomposition to nitrite and nitrate, laboratory synthesis, and formation of peroxynitrite from S-nitrosoglutathione (GSNO) and KO2.

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

Comparison of electrospray ionization, atmospheric pressure chemical ionization and atmospheric pressure photoionization for determining estrogenic chemicals in water by liquid chromatography tandem mass spectrometry with chemical derivatizations.

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

Automated analysis of 2-methyl-3-furanthiol and 3-mercaptohexyl acetate at ng L(-1) level by headspace solid-phase microextracion with on-fibre derivatisation and gas chromatography-negative chemical ionization mass spectrometric determination.

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

GC-MS/MS and LC-MS/MS studies on unlabelled and deuterium-labelled oleic acid (C18:1) reactions with peroxynitrite (O=N-O-O⁻) in buffer and hemolysate support the pM/nM-range of nitro-oleic acids in human plasma.

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.

Simultaneous determination of thyreostatic residues in animal tissues by matrix solid-phase dispersion and gas chromatography-mass spectrometry.

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

Analysis of trace levels of pesticides in rainwater by SPME and GC-tandem mass spectrometry after derivatisation with PFBBr.

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:

Quantification of carbonate by gas chromatography-mass spectrometry.

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

Urinary concentrations of organophosphorus insecticide metabolites in Japanese workers.

Jun Ueyama et al.

Chemosphere, 87(11), 1403-1409 (2012-03-30)

A recent development in analytical chemistry has enabled us to monitor systemic organophosphorus insecticide (OP) exposure at individual levels. At present, however, limited data are currently available on urinary OP metabolite levels worldwide. The purpose of this study was to

Determination of trace amounts of bisphenol A in urine by negative-ion chemical-ionization-gas chromatography/mass spectrometry.

Tadashi Tsukioka et al.

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 19(1), 151-153 (2003-02-01)

We improved an analytical method for determining trace amounts of bisphenol A (BPA) in urine. BPA was subjected to enzymolysis and then to solid phase extraction with a C18 cartridge. The extract was eluted with methanol, and the eluate was

Stable-isotope dilution GC-MS approach for nitrite quantification in human whole blood, erythrocytes, and plasma using pentafluorobenzyl bromide derivatization: nitrite distribution in human blood.

Alexandra Schwarz et al.

Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 879(17-18), 1485-1495 (2010-06-15)

Previously, we reported on the usefulness of pentafluorobenzyl bromide (PFB-Br) for the simultaneous derivatization and quantitative determination of nitrite and nitrate in various biological fluids by GC-MS using their (15)N-labelled analogues as internal standards. As nitrite may be distributed unevenly

Journal of Chromatography A, 539, 232-232 (1991)

Analysis of steroid estrogens in water using liquid chromatography/tandem mass spectrometry with chemical derivatizations.

Ying-Hsuan Lin et al.

Rapid communications in mass spectrometry : RCM, 21(13), 1973-1983 (2007-05-26)

Even in trace amounts, estrogens such as 17beta-estradiol (E2), estrone (E1), estriol (E3), and 17alpha-ethinyl estradiol (EE2) may have adverse effects on humans and the aquatic ecosystem. Therefore, it is essential to be able to measure trace amounts of steroid

General method for determining ethylene oxide and related N7-guanine DNA adducts by gas chromatography-electron capture mass spectrometry.

M Saha et al.

Journal of chromatography. A, 712(2), 345-354 (1995-10-13)

A 112-micrograms sample of DNA was spiked with 103 pg of N7-(2'-hydroxyethyl)guanine and 100 pg of N7-(2'-hydroxyethyl-d4)guanine, the internal standard. The sample was subjected to the following sequence of steps: heating at 100 degrees C, precipitation of the DNA with

Sequential Co-immobilization of Enzymes in Metal-Organic Frameworks for Efficient Biocatalytic Conversion of Adsorbed CO2 to Formate.

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

Improved solid-phase extraction procedure for the isolation and in-sorbent pentafluorobenzyl alkylation of polyfunctional mercaptans. Optimized procedure and analytical applications.

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

[Solid phase microextraction and derivatization of sulfide in blood with pentafluorobenzylbromide].

Junting Liu et al.

Wei sheng yan jiu = Journal of hygiene research, 32(6), 620-621 (2004-02-18)

Solid phase microextraction (SPME) and derivatization with pentafluorobenzylbromide for sulfide in blood was presented in the paper. The derivative of sulfide was extracted for 20 min at the condition of room temperature by a polydimethylsiloxane fiber. 1,3,5-tribromobenzene (IS) was used

Determination of bisphenol A, triclosan and their metabolites in human urine using isotope-dilution liquid chromatography-tandem mass spectrometry.

Gilles Provencher et al.

Journal of chromatography. A, 1348, 97-104 (2014-05-20)

Bisphenol A (BPA) and triclosan (TCS) are ubiquitous environmental phenols exhibiting endocrine disrupting activities that may be involved in various health disorders in humans. There is a need to measure separately free forms and conjugated metabolites because only the former

Unique pentafluorobenzylation and collision-induced dissociation for specific and accurate GC-MS/MS quantification of the catecholamine metabolite 3,4-dihydroxyphenylglycol (DHPG) in human urine.

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

LC-MS/MS analysis of uncommon paracetamol metabolites derived through in vitro polymerization and nitration reactions in liquid nitrogen.

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

[Ureido-¹⁵N]citrulline UPLC-MS/MS nitric oxide synthase (NOS) activity assay: development, validation, and applications to assess NOS uncoupling and human platelets NOS activity.

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

Neural metabolic imbalance induced by MOF dysfunction triggers pericyte activation and breakdown of vasculature.

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

In-source formation of N-acetyl-p-benzoquinone imine (NAPQI), the putatively toxic acetaminophen (paracetamol) metabolite, after derivatization with pentafluorobenzyl bromide and GC-ECNICI-MS analysis.

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

1/2