Showing papers by "Ernst Bayer published in 1989"
TL;DR: A new method for the determination of metals in waters by flame atomic-absorption spectrometry is described and higher preconcentration factors can be achieved and lower concentrations can be determined.
40 citations
TL;DR: In this article, an improved continuous-flow nuclear magnetic resonance (NMR) probe showing excellent characteristics with respect to signal line shape and resolution is described, and the stationary sensitivity is about 60% of that of rotating NMR tubes in a one-pulse experiment.
40 citations
TL;DR: In this article, two different types of silica substrates uniformly modified with reversed-phase high-performance liquid chromatographic (RP-HPLC) phases obtained with mono-, di- and trifunctional octadecylsilanes were subjected to artificial ageing under simulated routine conditions and were subsequently analyzed and evaluated.
37 citations
36 citations
TL;DR: In this article, a method for the separation and preconcentration of actinide elements in liquid-phase using a water-soluble polymer with oxine groups was developed, and the optimum conditions of separation in conjunction with membrane filtration were investigated and discussed.
Abstract: A method for the separation and preconcentration of actinide elements in liquid-phase using a water-soluble polymer with oxine groups was developed. The optimum conditions of separation in conjunction with membrane filtration were investigated and discussed. It was shown that an aqueous solution of a poly(ethyleneimine) derivative with 8-hydroxy quinoline groups is suitable for the process proposed, whereas the basis polymer itself was not capable to separate actinides. A retention of 99% was attained for U(VI), Pu(IV), and trivalent transplutonium elements when using a 2% solution of the polymer reagent at a pH range between 5 and '7. Stripping off the TPE elements from the polymer and their separation from TU was achieved by using an aqueous solution with pH 2. The analytical application of the method is discussed.
33 citations
24 citations
22 citations
TL;DR: In this article, a nucleosil was modified with various amounts of iron(III) and this masking had an influence on the retention of bases, which can be explained by the presence of silanediols with different reactivities.
16 citations
TL;DR: The enantiomeric purity of commercially available amino acids has been determined down to 0.0 1 % before and after recrystallization as discussed by the authors, and the amino acids have been transformed smoothly into the volatile N-trifluoroacetyl amino acid methyl esters, and were investigated by gas chromatography on the chiral stationary phase Chirasil- Val.
14 citations
11 citations
TL;DR: In this paper, a new approach to anion exchange extraction of such anions by water-soluble polymeric quarternary ammonium salts is suggested in conjunction with membrane filtration.
Abstract: The problems of solvent extraction and ion-exchange-based quantitative enrichment of anions having high hydration energies in aqueous solutions using water-insoluble quaternary ammonium salts are discussed. A new approach to anion exchange extraction of such anions by water-soluble polymeric quarternary ammonium salts is suggested in conjunction with membrane filtration. The retention of oxo anions of arsenic(V)r phosphorus(V), chromium(VI), selenium(IV) and of the fluoride ion with the permethylated derivative of poly-(ethyleneimine) and the influence of different salts on the retention of the anions have been studied and the possibility of quantitative retention of these anions has been demonstrated. For example, the retention for arsenic(V) was found to be 92% and 89% for fluoride with 2% polymer and a filtration factor of seven. After extraction the oxo anions can be stripped off easily in the cell solution up to 99% by 0.1 M HCl or a 0.15 M solution of sodium salts.
Patent•
18 Jan 1989TL;DR: In this paper, the authors showed that both non-alkylated and alkylated copolymers are distinguished by strong absorption of water, and that both the nonalkylation and the alkylation copolymer are distinguishable by strong water absorption.
Abstract: Condensation of polyethylene glycol omega , omega '-dihalides and polyamines gives basic copolymers which are converted into ammonium salts by alkylation. Both the non-alkylated and the alkylated copolymers are distinguished by strong absorption of water.