The possibilities of radioanalytical separation by isotopic exchange with metal chelate complexes and metal sulphide precipitates
fixed in paper have been examined on the model system203Hg2++58Co2++65Zn2++24Na+.
Authors:Cs. Mohácsi-Farkas, J. Farkas, L. Mészáros, O. Reichart and É. Andrássy
Thermal stability of vegetative cells of Listeria monocytogenes, Escherichia coli and Lactobacillus plantarum was studied by counting viable fractions and determining DSC curves of their suspensions. DSC curves in the 5–99°C range showed a series of endothermic transitions between 50 and 60°C, where the heat destruction of cells occurred. Heat denaturation of DNA required a higher temperature than cell killing. Thermal death was strongly influenced by the pH, composition and NaCl content of the suspending buffer. A mathematical model developed by us enabled comparison of DSC peak temperatures and temperatures required for loss of viability.
Authors:Z. Aigner, R. Heinrich, E. Sipos, G. Farkas, A. Ciurba, O. Berkesi and P. Szabó-Révész
The compatibility of aceclofenac with various tableting excipients was investigated by means of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). The excipients applied in the direct pressing retard tablets were Carbopol 940, hydroxypropyl-methyl-cellulose, microcrystalline cellulose, Aerosil 200 and magnesium stearate. The ingredients alone and their 1:1 (w/w) binary mixtures were investigated before and after accelerated storage. An interaction was observed only between aceclofenac and magnesium stearate. The DSC and FT-IR examinations indicated formation of the magnesium salt of aceclofenac. For the other mixtures, there was no incompatibility between the components.