Abstract: Method for the determination of a component in a liquid which component is selected from ions, polar substances lipophilic substances, which comprises contacting a liquid sample containing said component with, and allowing same to act upon, a complex ligand or host molecule which is selective toward the component, said complex ligand or host molecule being bonded to a chromophore material, and measuring the change of extinction or the wavelength displacement of the resulting mixture as a measure of the initial content of said component; corresponding reagent test kits are also provided. The complex ligands or host molecules include cyclodextrins, cyclophanes, crown ethers, cryptands, podands valinomycin, gramacidin and monactin.

Abstract: Electrochemical storage cell or battery of the alkali metal and sulfur type operable in the range from about 100.degree. to 200.degree. C. A solvent is added to the alkali sulfides in the cathode chamber to at least partially dissolve the sulfides. In addition to other good properties, the solvent of the invention is outstanding with respect to stability, i.e. can be used for very long periods of time under the conditions of operation without decomposing.