Abstract: The invention relates to an improved process for the production of practically non-hygroscopic, easily grindable copper(II) sulfate monohydrate which is stable even in finely ground state and can be applied as trace element additive in animal fodders, by neutralizing the free sulfuric acid content of copper(II) sulfate pentahydrate with sodium, potassium or ammonium hydroxide, carbonate or hydrocarbonate (further on: alkaline agent) and removing four moles of its crystal water content by drying at 80.degree. to 150.degree. C. for at least 30 minutes. The improvement according to the invention consists in that copper(II) sulfate pentahydrate, melted in its own crystal water, is treated with 3 to 20% by weight, preferably 5 to 8% by weight, of an alkaline agent calculated as sodium carbonate for the weight of the copper(II) sulfate pentahydrate, over the stoichiometric amount required to neutralize the free sulfuric acid content.

Abstract: A process for measuring the isotope content of substances containing .sup.3 H or .sup.3 H and .sup.14 C isotopes in the gas phase, by converting the hydrogen content of the sample into water and the carbon content of the sample to a gaseous substance in simultaneous oxidation processes, separating the formed water and carbon dioxide, reconverting the .sup.3 H content of the water into gaseous form, introducing the gases containing .sup.3 H and possibly also .sup.14 C separately into a detecting unit, and determining the radioactivity of said gases, in which the tritium content of the water carrying the .sup.3 H radio-activity is bonded on a contact catalyst capable of water retention or adsorption and containing activated hydrogen, the gaseous mixture, containing also .sup.14 CO.sub.2 when a sample of .sup.