Abstract: The conditions of forming complexes stable in the NMR time scale, for alkali-earth metals-strontium, barium and calcium were investigated. Most suitable ligand for forming such complexes-cryptand C222 was found ¹³C NMR spectra of akali-earth metal and alkali metal-sodium, potassium and lithium complexes in deuterochloroform were studied and interpreted. ¹³C NMR signals of free ligand and its complexes with alkali earth metals which should be used for analytical purposes were assigned. ¹³C NMR spectra of different mixtures of alkali-earth and alkali metals in chloroform were studied. It was shown that in the spectrum of a mixture of barium, calcium and strontium in concentration of 0.001M for each metal under excess amount of free ligand, individual signals corresponding to free ligand and each of the ions were observed. These signals could be integrated with sufficient accuracy and each characterizes concentration of one of the metal ions correspondingly. These observed for the first time results allow to develop, in principle, a new method of inorganic analysis by ¹³C NMR spectroscopy. Suggestions of analytical methods for the NMR-determination of alkali-earth metals in their mixture were discussed in detail. The method could be extended to the analysis of more complicated mixtures including alkali metal series. Spectra were run on Varian XL-200 spectrometer.

Key words: Alkali-earth ion determination, Cryptand complexes, NMR analytical application