PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “ION EXCHANGE RESINS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
PubMed1976

The separation of methyl ethers of methyl 2-acetamido-2-deoxy-D-glucopyranosides on a strongly basic ion-exchange resin.

The methyl ethers of methyl 2-acetamido-2-deoxy-alpha- and -beta-D-glucopyranoside can be isolated on a preparative scale by chromatography on Dowex-1(HO-) resin. This procedure greatly simplifies the purification of methyl ethers, and has been used to isolate the methyl ethers produced by partial methylation of methyl 2-acetamido-2-deoxy-beta-D-glucopyranoside. The separations are thought to depend on an ion-exchange process in which all the free hydroxyl groups are involved. It is concluded that the following acidity sequence holds: HO-4 greater than HO-3 greater than HO-6.

Acetylglucosamine↗
PubMed2004

Hydration of halide anions in ion-exchange resin and their dissociation from cationic groups.

The local structures of Cl- and Br- in an anion-exchange resin have been investigated by X-ray absorption fine structure (XAFS). The resins, which have been equilibrated under various partial water vapor pressures to allow the anions to have various hydration numbers, are provided for XAFS measurements. The XAFS spectra indicate that two scattering groups around the counteranion are present, that is, water molecules and an ion-exchange group. Regression analyses allow the separation of the contributions from these two scattering groups; thus, the average hydration number (N) is determined. The hydration number linearly increases with increasing the number of water molecules (n) adsorbed by an ion-exchange pair (an ion-exchange group and a counteranion) until the ion-exchange pair adsorbs ca. 3 water molecules, indicating that all of the adsorbed water molecules coordinate the counteranion. However, an increase in N with increasing n becomes small as n exceeds 3; N finally reaches 3.9 (+/-0.4) for Cl- and ca. 3.4 (+/-0.5) for Br-. Detailed studies of the water adsorption isotherms imply that the maximum hydration number of these anions is three when they are bound by the ion-exchange groups, and as more water molecules are supplied, they are dissociated from the ion-exchange groups; ca. 40% of total counteranions are dissociated from the ion-exchange groups.

Journal Article↗
PubMedDate not supplied

[Sorption of enzymes on ion exchange resins of various structure].

The isothermic adsorption of microbial and animal enzymes on carboxyl and sulpha-cation exchange resins was studied. The adsorption isotherms are curves with a maximum. The adsorption of alpha-amylase was studied in the presence of organic solvents. It was found that organic solvents influenced the isothermic adsorption of alpha-amylase, which is associated with changes in the interactions between protein molecules in solution. The adsorption system was in equilibrium in all the cases.

Adsorption↗
PubMed1983

The measurement of monoamine oxidase activity: a comparison of the ion exchange resin column method and the solvent extraction method.

A comparison was made of monoamine oxidase (MAO) activity level; the level was obtained by quantification of radiolabeled deaminated metabolites separated from unchanged amines by two different methods. MAO activity in whole brain of male and female mice from five inbred strains was measured with three substrates PEA, TYR, and 5-HT to examine apparent variations in enzyme activity level with substrate metabolized. Levels of activity measured by the two separation methods were equivalent, as demonstrated by comparison of population mean activity levels and by Pearson product-moment correlation coefficients (0.92, 0.93, and 0.83 for PEA, TYR, and 5-HT, respectively).

Animals↗
PubMed1983

Sample preparation with ion-exchange resin before liquid-chromatographic determination of plasma catecholamines.

Estimation of plasma catecholamine concentrations by "high-performance" liquid chromatography, although increasingly used, still presents difficulties. We describe a method for clean-up of plasma samples on cation-exchange resin before they are extracted with alumina. This procedure eliminates many of the interfering compounds often present in plasma extracts prepared with the alumina treatment alone. The method can be adapted to use commercially available disposable cation-exchange columns.

Catecholamines↗
PubMedDate not supplied

[Simultaneous estimation of catecholamines and serotonin after purification on ion exchange resin].

A general fluorimetric method was developed for determination of noradrenaline, adrenaline, dopamine and serotonin in a single sample. Purification of samples was carried out on columns of Dowex 50X4 and 10 in sodium form. As judget by an internal standard the yield of noradrenaline and adrenaline was about 90% and of dopamin -- about 75%. Serotonin was determined by means of a condensation reaction with ninhydrin. A more stable fluorescence of serotonin samples was provided by an increase in warming-up time up to 55 min. Treatment of control probes with iodine solution permitted to eliminate an unspecific fluoresence of the tissues studied. The yield of serotonin was about 75% as estimated by an internal standard.

Chromatography, Ion Exchange↗