The designation “scourge of mankind” has been attached to parasitic infections such as Chagas' heart disease, sleeping sickness, and malaria. In many countries of the world they lead to human misery and massive socio-medical problems. Several approaches are possible for the design of chemotherapeutic agents that can interfere as enzyme inhibitors with the metabolism of parasites. For instance, structural motifs of an enzyme and its natural substrates can be expolited to control the kinetics of the enzyme–substrate interactions, and thus substrate analogues can influence the enzyme as inhibitors at various stages of the catalytic cycle. The results may be irreversible inhibition, destabilization of the enzyme's structure, or an alteration of its substrate specificity. Glutathione reductase and trypanothione reductase are target enzymes for this strategy of drug design in the fight against tropical diseases.

Since the ligation of peptide fragments in vivo is meaningless, no natural enzyme is capable of replacing chemical coupling methods, which have the danger of racemization in segment condensation. Native proteases and those altered by protein design as well as catalytic antibodies may serve as peptide ligases, as demonstrated recently with subtiligase in the chemoenzymatic synthesis of R Nase A.

Strontium-90 is one of the most poisonous radionuclides. Its toxicity results from its long half-life of 28.5 years and permanent deposition in the blood-forming bone system. Strontium-90 is formed in high yields during the nuclear fission of uranium-235 and plutonium-239. The classic analytical procedure for the determination of ⁹⁰Sr, which relies on the β⁻-radiation of the daughter nuclide yttrium-90, necessitates the chemical removal of all accompanying nuclides. This method requires the Sr/Y ratio to be at equilibrium which takes about two to three weeks to achieve—far too long for the analysis of acute contaminations. Three communications deal with new procedures for ultra-trace analysis using complex physical detection methods (resonance ionization and accelerator mass spectrometry) and high-performance separation techniques (high-performance ion chromatography, HPIC) are presented. In accordance with the strategies of the German Federal Ministry of the Environment, Nature Conservation, and Nuclear Safety, precision methods are described for the determination of the strontium-90 content in aerosols. These techniques yield data for calculations of the spread of contaminants, which in turn yield results that can be verified in various samples with the aid of the novel fast detection method (HPIC with on-line detectors). The three analytical procedures are set up in a modular manner and can therefore be utilized in variable combinations. They also indicate the high level of refinement achieved by modern ultra-trace analyses.

Strontium-90 is one of the most poisonous radionuclides. Its toxicity results from its long half-life of 28.5 years and permanent deposition in the blood-forming bone system. Strontium-90 is formed in high yields during the nuclear fission of uranium-235 and plutonium-239. The classic analytical procedure for the determination of ⁹⁰Sr, which relies on the β⁻-radiation of the daughter nuclide yttrium-90, necessitates the chemical removal of all accompanying nuclides. This method requires the Sr/Y ratio to be at equilibrium which takes about two to three weeks to achieve—far too long for the analysis of acute contaminations. Three communications deal with new procedures for ultra-trace analysis using complex physical detection methods (resonance ionization and accelerator mass spectrometry) and high-performance separation techniques (high-performance ion chromatography, HPIC) are presented. In accordance with the strategies of the German Federal Ministry of the Environment, Nature Conservation, and Nuclear Safety, precision methods are described for the determination of the strontium-90 content in aerosols. These techniques yield data for calculations of the spread of contaminants, which in turn yield results that can be verified in various samples with the aid of the novel fast detection method (HPIC with on-line detectors). The three analytical procedures are set up in a modular manner and can therefore be utilized in variable combinations. They also indicate the high level of refinement achieved by modern ultra-trace analyses.

Strontium-90 is one of the most poisonous radionuclides. Its toxicity results from its long half-life of 28.5 years and permanent deposition in the blood-forming bone system. Strontium-90 is formed in high yields during the nuclear fission of uranium-235 and plutonium-239. The classic analytical procedure for the determination of ⁹⁰Sr, which relies on the β⁻-radiation of the daughter nuclide yttrium-90, necessitates the chemical removal of all accompanying nuclides. This method requires the Sr/Y ratio to be at equilibrium which takes about two to three weeks to achieve—far too long for the analysis of acute contaminations. Three communications deal with new procedures for ultra-trace analysis using complex physical detection methods (resonance ionization and accelerator mass spectrometry) and high-performance separation techniques (high-performance ion chromatography, HPIC) are presented. In accordance with the strategies of the German Federal Ministry of the Environment, Nature Conservation, and Nuclear Safety, precision methods are described for the determination of the strontium-90 content in aerosols. These techniques yield data for calculations of the spread of contaminants, which in turn yield results that can be verified in various samples with the aid of the novel fast detection method (HPIC with on-line detectors). The three analytical procedures are set up in a modular manner and can therefore be utilized in variable combinations. They also indicate the high level of refinement achieved by modern ultra-trace analyses.

Under cathodic conditions a polymer film forms on an electrode when C₆₀O is first reduced in the presence of Bu₄NClO₄ in toluene/acetonitrile and then oxidized. Films with thicknesses of up to 3 μm can be produced by repeated cyclic voltammetry. Evidence for ionic as well as electronic conductivity of this fullerene polymer is also provided.

Discrete neutral assemblies in solution can be studied with the analytical method described here. A prerequisite is that one of the components contains an ion-complexing site, for example a crown ether unit. When alkali metal ions are added, charged assemblies form, which can be examined by electrospray mass spectrometry (ESMS) without disruption of their hydrogen bonds. IL in the title stands for ion labeling.

Rather than CH or CC bonds, Pr⁺ activates CF bonds in the gas phase in a variety of aliphatic and aromatic fluorocarbons; PrF⁺ and PrO⁺ react analogously. This first general example of preferential CF bond activation in the gas phase allows interesting conclusions to be drawn regarding the importance of 4f electrons for the reactivity of isolated lanthanide species. The existence of neutral PrF and PrF₂ in the gas phase was also proven by neutralization–reionization mass spectrometry (NRMS).