Selectivity study of large rings-crown-6 ethers for large ions

Abstract EN

Ion selective microelectrodes were prepared by coating the tip of a pre conditioned silver wire with a layer of a coating matrix containing benzo-18- crown-6.

The microelectrodes were inserted in a system of flow analysis as selective electrodes for potassium, strontium and lead.

The selectivity coefficients were obtained according to the matched potential, fixed interference, and separate solution methods.

Selectivities of potassium over sodium, lithium, calcium and magnesium of strontium over calcium and magnesium, and of lead over strontium, calcium and magnesium were demonstrated.

The change in selectivity with change of the side chain is also illustrated.

A correlation was found between the ability of 18-C-6 ether to extract metals into organic phases and their selectivity when used as ionophores in ion-selective electrodes.