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Isotopical labeling

Studies to determine the nature of intermediate species have been made on a variety of transition metals, and especially on Pt, with emphasis on the Pt(lll) surface. Techniques such as TPD (temperature-programmed desorption), SIMS, NEXAFS (see Table VIII-1) and RAIRS (reflection absorption infrared spectroscopy) have been used, as well as all kinds of isotopic labeling (see Refs. 286 and 289). On Pt(III) the surface is covered with C2H3, ethylidyne, tightly bound to a three-fold hollow site, see Fig. XVIII-25, and Ref. 290. A current mechanism is that of the figure, in which ethylidyne acts as a kind of surface catalyst, allowing surface H atoms to add to a second, perhaps physically adsorbed layer of ethylene this is, in effect, a kind of Eley-Rideal mechanism. [Pg.733]

When a molecule adsorbs to a surface, it can remain intact or it may dissociate. Dissociative chemisorption is conmion for many types of molecules, particularly if all of the electrons in the molecule are tied up so that there are no electrons available for bonding to the surface without dissociation. Often, a molecule will dissociate upon adsorption, and then recombine and desorb intact when the sample is heated. In this case, dissociative chemisorption can be detected with TPD by employing isotopically labelled molecules. If mixing occurs during the adsorption/desorption sequence, it indicates that the mitial adsorption was dissociative. [Pg.295]

Dihydrogen (H2) is similarly protonated to by superacids, as was shown by studies using isotopic labeling. The structure of again involves 2e-3c bonding. [Pg.101]

Isotopic labeling with CD3, substituents effects (56), and general trends in the thiazole series (271) allowed a complete assignement of the major infrared bands for a series of 2-methylthiothiazoles. [Pg.405]

The study of the infrared spectrum of thiazole under various physical states (solid, liquid, vapor, in solution) by Sbrana et al. (202) and a similar study, extended to isotopically labeled molecules, by Davidovics et al. (203, 204), gave the symmetry properties of the main vibrations of the thiazole molecule. More recently, the calculation of the normal modes of vibration of the molecule defined a force field for it and confirmed quantitatively the preceeding assignments (205, 206). [Pg.53]

The first mass spectrometric investigation of the thiazole ring was done by Clarke et al. (271). Shortly after, Cooks et al., in a study devoted to bicydic aromatic systems, demonstrated the influence of the benzo ring in benzothiazole (272). Since this time, many studies have been devoted to the influence of various types of substitution upon fragmentation schemes and rearrangements, in the case of alkylthiazoles by Buttery (273) arylthiazoles by Aune et al. (276), Rix et al. (277), Khnulnitskii et al. (278) functional derivatives by Salmona el al. (279) and Entenmann (280) and thiazoles isotopically labeled with deuterium and C by Bojesen et al. (113). More recently, Witzhum et al. have detected the presence of simple derivatives of thiazole in food aromas by mass spectrometry (281). [Pg.81]

The stereochemical relationship between the reactant and the product revealed by the isotopic labeling shows that oxygen becomes bonded to carbon on the same side from which H IS lost As you will see m this and the chapters to come determining the three dimensional aspects of a chemical or biochemical transformation can be a subtle yet powerful tool for increasing our understanding of how these reactions occur... [Pg.285]

Substitution of deuterium for hydrogen at the a carbon atom of an aldehyde or a ketone is a convenient way to introduce an isotopic label into a molecule and is readily carried out by treating the carbonyl compound with deuterium oxide (D2O) and base... [Pg.768]

When benzoic acid is allowed to stand in water enriched in isotopic label becomes incorporated into the benzoic acid The reaction is cat alyzed by acids Suggest an explanation for this observation... [Pg.813]

In an extension of the work described m the preceding section Bender showed that basic ester hydrolysis was not concerted and like acid hydrolysis took place by way of a tetrahedral intermediate The nature of the experiment was the same and the results were similar to those observed m the acid catalyzed reaction Ethyl benzoate enriched m 0 at the carbonyl oxygen was subjected to hydrolysis m base and samples were isolated before saponification was complete The recovered ethyl benzoate was found to have lost a por tion of Its isotopic label consistent with the formation of a tetrahedral intermediate... [Pg.855]

A more recent experimental technique employs C as the isotopic label Instead of locating the position of a label by a laborious degradation procedure the NMR spectrum of the natural product is recorded The signals for the carbons that are enriched m are far more intense than those corresponding to carbons m which IS present only at the natural abundance level... [Pg.1092]

Isotopically Labeled Compounds. The hydrogen isotopes are given special names H (protium), H or D (deuterium), and H or T (tritium). The superscript designation is preferred because D and T disturb the alphabetical ordering in formulas. [Pg.216]

Isotopically labeled compounds may be described by inserting the italic symbol of the isotope in brackets into the name of the compound for example, H C1 is hydrogen chloride[ CZ] or hydrogen chloride-36, and H C1 is hydrogen H chloride[ CZ] or hydrogen-2 chloride-38. [Pg.216]

Troost and Olavesen investigated the application of an internal standardization to the quantitative analysis of polynuclear aromatic hydrocarbons. The following results were obtained for the analysis of the analyte phenanthrene using isotopically labeled phenanthrene as an internal standard... [Pg.133]

Before sample preparation, surrogate compounds must be added to the matrix. These are used to evaluate the efficiency of recovery of sample for any analytical method. Surrogate standards are often brominated, fluorinated, or isotopically labeled compounds that are not expected to be present in environmental media. If the surrogates are detected by GC/MS within the specified range, it is... [Pg.299]

The proportionality between the concentration of chromophores and the measured absorbance [Eqs. (6.8) and (6.9)] requires calibration. With copolymers this is accomplished by chemical analysis for an element or functional group that characterizes the chromophore, or, better yet, by the use of isotopically labeled monomers. [Pg.461]

John Wiley Sons, Cornell University ms 125,000 CD-ROM, tape isotopic labeled compound QuaUty Index algorithm... [Pg.122]

Moleeular biology eloning expression isotope labeling of protein target... [Pg.274]

Alternatively, radiohalogen-labeled compounds may be prepared by way of isotopic labeling from the unlabeled bromo or iodo derivatives by various two-step reaction sequences. Examples include the use of trialkylsilyl synthons as described in References 10—13, and the use of boronic acid synthons as described in References 14 and 15. [Pg.480]

Benzoates. The selective debenzoylation of sucrose octabenzoate [2425-84-5] using isopropylamine in the absence of solvents caused deacylation in the furanose ring to give 2,3,4,6,1/3/6 -hepta- and 2,3,4,6,1/6 -hexa-O-benzoyl-sucroses in 24.1 and 25.4% after 21 and 80 hours, respectively (54). The unambiguous assignment of partially benzoylated sucrose derivatives was accompHshed by specific isotopic labeling techniques (54). Identification of any benzoylated sucrose derivative can thus be achieved by comparison of its C-nmr carbonyl carbon resonances with those of the assigned octabenzoate derivative after benzoylation with 10 atom % benzoyl—carbonyl chloride in pyridine. [Pg.33]

The study of the biosynthesis of vitamin B 2 is a saga whose resolution, due primarily to Battersby (80—83) and Scott (84,85), requited an effort on the same magnitude as the total synthesis. It was only when recent molecular biology tools became available to complement en2ymology, isotopic labeling, chemical synthesis, and spectroscopy that solution of this problem became possible. [Pg.117]


See other pages where Isotopical labeling is mentioned: [Pg.1439]    [Pg.353]    [Pg.24]    [Pg.45]    [Pg.57]    [Pg.81]    [Pg.319]    [Pg.646]    [Pg.826]    [Pg.852]    [Pg.852]    [Pg.854]    [Pg.982]    [Pg.1096]    [Pg.1238]    [Pg.114]    [Pg.353]    [Pg.321]    [Pg.228]    [Pg.228]    [Pg.475]    [Pg.206]    [Pg.480]    [Pg.497]    [Pg.71]   
See also in sourсe #XX -- [ Pg.42 , Pg.122 , Pg.136 , Pg.288 , Pg.291 , Pg.299 , Pg.378 ]




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1-Serines, isotopically labelled, synthesis

18<). isotopic labelling with

Acetylene isotopic labelling

Acetylenes isotopically labelled

Alkene isotopically labeled

Alkenes isotopically labelled

Amino acid isotopically labeled

Amino isotope-labeled

Amino isotopically labeled

Analytical methods isotope labelling

And isotopic labeling

And isotopic labelling

Benzenes, isotopically labelled, synthesis

Benzoic acid, labelled with isotopic

Biotransformations in the Preparation of Compounds Labeled with Carbon and Hydrogen Isotopes

Calf, G. E., Garnett, J. L., isotopic Hydrogen Labeling of Heterocyclic Compounds

Carbanions isotopic label

Carbon 14C as isotopic label

Carbon 14C as isotopic label in Claisen

Carbon monoxide, labelled with isotopic

Carbon selective isotopic labeling

Carbon, isotopic, hydrocarbons labeled

Chemical labeling isotope-coded affinity tags

Chemical labeling isotopic tags

Chemical labeling stable isotopic labels

Chemical names isotopic labeling

Chemical reactions isotopic labeling

Combinatorial isotope labeling

Cyclohexane isotopically labelled

Deuterium isotope labeling

Deuterium isotopic labelling with

Diazo compounds isotopically labelled

Diazomethane isotopically labeled

Differential isotope labeling

Differential stable isotope labeling strategy

Epoxidation isotope labeling experiment

Ester hydrolysis isotopic labels

Esterification isotope labels

Ethene isotopically labelled

Expressed protein ligation segmental isotope labeling

E„ elimination isotopic labelling

Fecal Balance Studies (Single Isotopic Label)

Food source, isotopic labeling

Formulae isotopic labelling

Furans, isotopically labelled

Galactose isotopically labeled

Glycine isotopically labeled

Glycines, isotopically labelled, synthesis

H-D-T Isotope Exchange and Labeled Starches

Heavy Isotope Labelling

Heterocyclic chemistry isotopic hydrogen labeling

Heterocyclic compounds isotopic hydrogen labeling

High concentration isotope label, SANS

Hydrogen, isotopes sugars specifically labeled with

Incorporating isotopically labeled

Indirect reduction of halides and isotopic labelling via organomagnesium compounds

Indoles isotopically labelled

Infrared spectroscopy isotope labeling

Isomerization isotopic labelling

Isothiazoles Isotopic hydrogen labeling of heterocyclic

Isotop ically labelled

Isotope Tagging and Labeling Techniques for Protein Quantification

Isotope isotopic labeling

Isotope isotopic labeling

Isotope label

Isotope label

Isotope labeled sugars

Isotope labeled sugars degradation

Isotope labeled sugars synthesis

Isotope labeling diffusion

Isotope labeling olefins

Isotope labeling studies

Isotope labeling techniques

Isotope labeling, chemical

Isotope labeling, chemical Subject

Isotope labeling/spiking

Isotope labelling advances

Isotope labelling and NMR

Isotope labelling techniques

Isotope-coded affinity tag labeling

Isotope-coded protein label

Isotope-coded protein label chemical labeling

Isotope-labeled amino acids

Isotope-labeled carbon dioxide

Isotope-labeled internal standard

Isotope-labeled proteins

Isotope-labeling detection

Isotope-labeling experiments

Isotope-labeling experiments, amine

Isotope-labelled

Isotope-labelled

Isotope-labelled sulfur

Isotope-labelling

Isotopes labeling

Isotopes s. Compounds labeled

Isotopes sugars labeled with

Isotopes, stable multiple labelling with

Isotopic Label Incorporation Determination

Isotopic Labeling and Kinetic Isotope Effects

Isotopic Labelling of Biosynthetic Proteins

Isotopic hydrogen labeling

Isotopic hydrogen labeling of heterocyclic

Isotopic hydrogen labeling of heterocyclic compounds, one-step methods

Isotopic labeled fatty acid

Isotopic labeled fitly acid

Isotopic labeling

Isotopic labeling

Isotopic labeling channels

Isotopic labeling coupled systems

Isotopic labeling cross-over experiments

Isotopic labeling decarbonylation

Isotopic labeling deuteration

Isotopic labeling double labeled proteins

Isotopic labeling effects

Isotopic labeling experiments

Isotopic labeling kinetic isotope effects

Isotopic labeling nuclear spins

Isotopic labeling of heterocyclic compounds, one-step methods

Isotopic labeling reactions

Isotopic labeling resonance assignment

Isotopic labeling studies

Isotopic labeling tracer techniques

Isotopic labeling with

Isotopic labeling, ANRORC reaction

Isotopic labeling, alkynes

Isotopic labeling, alkynes mechanism

Isotopic labeling, categories

Isotopic labeling, mixed

Isotopic labeling, slow exchange

Isotopic labeling, stereospecific

Isotopic labeling, value

Isotopic labelled

Isotopic labelled

Isotopic labelled product

Isotopic labelling

Isotopic labelling

Isotopic labelling aldol reactions

Isotopic labelling and Cannizzaro reaction

Isotopic labelling applications

Isotopic labelling approaches

Isotopic labelling carboxylic acid derivatives

Isotopic labelling in aldol reaction

Isotopic labelling in hydrolysis of aspirin

Isotopic labelling indole

Isotopic labelling isoxazoles

Isotopic labelling radioactive

Isotopic labelling reactions

Isotopic labelling rearrangement

Isotopic labelling stable

Isotopic labelling studies

Isotopic labelling studies addition reactions

Isotopic labelling studies formation

Isotopic labelling studies pyrolysis

Isotopic labelling studies rearrangement

Isotopic labelling studies ring opening

Isotopic labelling studies synthesis

Isotopic labelling tritium-labelled benzene

Isotopic labelling use in biosynthetic studies

Isotopic labelling using bases

Isotopic labelling using basic reagents

Isotopic labelling with radioactive carbon

Isotopic labelling with stable isotopes

Isotopic labelling with tritium

Isotopic labelling, in mass spectrometry

Isotopic labelling/tracing

Isotopic labels

Isotopic labels

Isotopic labels bromide

Isotopic labels carbon

Isotopic labels chemical stability

Isotopic labels deuterium

Isotopic labels iodine

Isotopic labels monitoring

Isotopic labels nitrogen

Isotopic labels scrambling

Isotopic labels sulphur

Isotopic labels, randomization

Isotopic small labeling

Isotopically Labelled Heterocycles

Isotopically labeled

Isotopically labeled Isoxazoles

Isotopically labeled alkanes

Isotopically labeled amides

Isotopically labeled branched-chain amino acid

Isotopically labeled carbamates

Isotopically labeled compounds

Isotopically labeled esters

Isotopically labeled internal standard

Isotopically labeled molecules

Isotopically labelled

Isotopically labelled compounds

Isotopically labelled compounds formulae

Isotopically labelled magnesium

Isotopically labelled mechanistic studies using

Isotopically labelled organogermanium

Isotopically labelled organogermanium compounds

Isotopically labelled organotin compounds

Isotopically labelled phosgene

Isotopically-labeled carotenoids

Isotopically-labelled precursors

Labeled atoms reactions isotope transfer

Labeled with isotopes of hydrogen

Labeling and Kinetic Isotope Effects

Labeling techniques, hydrogen isotope

Labeling useful isotopes

Labeling with hydrogen isotopes

Labeling, stable isotope clusters

Labelled with isotopic

Labelled with isotopic oxidation

Metabolic stable isotope labeling

Metabolite isotope labeling

Methane isotopically labelled

Methanol, labelled with isotopic

Methionine, isotopically labelled

Neutron Diffraction from Isotopically Labelled Samples

Nitrogen isotopic labelling

Nuclear magnetic resonance isotopic labeling

Nuclear magnetic resonance spectroscopy isotopically labelled

Octane, isotopically labelled

Oxalic acid labelled with isotopic

Oxygen isotopic labels

PC isotopic labeling

Peptide derivatization stable isotope labeling

Peptide sequencing stable isotope labeling

Peptides stable isotope labeling

Potassium cyanide, labelled with isotopic

Preparation of Tritium-Labeled Compounds by Isotope Exchange Reactions

Product analysis, reaction intermediates and isotopic labelling

Propene isotopically labelled

Protein quantitation stable isotope label

Protein sequencing stable isotope labeling

Proteins chemical isotope labeling

Proteolytic stable isotope labeling

Pyruvic acid labelled with isotopic

Radio-isotope Labelling

Radioactive isotope labeling

Radioactive isotopic labels

Reductive elimination isotopic labeling

Results and discussion on isotopically labeled chains

SILAC (Stable Isotope Labelling

SILAC (stable isotope labeling by amino acids

SILAC (stable isotope labeling with amino acids in cell

Saturated isotopic labeling

Segmental isotopic labeling

Selective isotopic labelling

Sensitivity-enhancement techniques isotope labelling

Silver compounds isotopically labelled

Solid-state nuclear magnetic resonance isotope labeling

Specific isotopic labelling

Specifically labeled with isotopes

Specifically labeled with isotopes hydrogen

Spin-isotope-labelling techniqu

Square brackets isotopic labeling

Square brackets isotopically labelled compounds

Stable Isotope Labeling at the Peptide Level

Stable Isotope Labeling in Cell Culture (SILAC)

Stable Isotopic Labels Versus Radiotracers

Stable isotope labeled

Stable isotope labeling

Stable isotope labeling SILAC)

Stable isotope labeling by amino acids

Stable isotope labeling by amino acids in cell

Stable isotope labeling by amino acids in cell culture

Stable isotope labeling by amino acids in cell culture, SILAC

Stable isotope labeling in cell culture

Stable isotope labeling with amino acids

Stable isotope labeling with amino acids cell culture

Stable isotope labeling with amino acids in cell

Stable isotope labeling with amino acids in cell culture

Stable isotope labelled compounds as internal standards

Stable isotope labelling

Stable isotope-labeled internal standard

Stable isotopes (labelling compounds

Stable isotopic labels

Stable-isotope-labeled GSH

Stable-isotope-labeled analogues

Stereo-Array Isotope Labeling

Succinic acid labelled with isotopic

Sugars Specifically Labeled with Isotopes of Hydrogen

Sulphonic acids isotopically labelled

Sulphur labelled isotopes

Surfactants, isotopically labelled

Synthesis of Isotopically Labeled, Enantiomerically Pure Compounds

Thiophene, isotopically labelled

Triosephosphate isomerase isotope labeled

Tryptophan isotopic labelled

Use of Isotopically Labeled Compounds (Tracer Technique)

Use of Isotopically Labeled Molecules

Use of isotopic labelling

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