Process for the preparation of lipide soluble complexes of cations, application of the process and use of the complexes

A process for the determination of the concentration of cations and performing electrodialysis using a membrane made by the process which comprises reacting in said membrane an uncharged complex forming substance which forms lipide soluble complexes with the cations whose concentrations are to be determined, said uncharged complex forming substance having the formula I ##EQU25## in which X is selected from the group consisting of ##EQU26## wherein R" is selected from the group consisting of hydrogen and organic radicals,

• Y and Y' are independent from each other and are selected from the group consisting of oxygen and sulphur atoms and wherein in the compounds of formula I at least one X is other than an ester an an acid amide group, and wherein the radicals R are selected from the group consisting of hydrogen and organic radicals wherein two radicals R can form, together with the carbon atom and atoms to which they are bonded, a ring-structure which may be a heterocyclic ring;
• R.sub.1 and R.sub.2 are selected from the group consisting of hydrogen and organic radicals, and when R.sub.1 is an organic radical,
• R.sub.2 is selected from the group consisting of hydrogen and organic radicals, and wherein when R.sub.1 and R.sub.2 together with the nitrogen atom of a group ##EQU27## of formula I form a heterocyclic radical and when wherein R.sub.1 of the two groups ##EQU28## of the formula I form together a group which closes the substance of formula I to form a cyclic structure, a is a value selected from 0 and in integer having a maximum value of 11 and the n's are independent from each other and are integers of from 1 - 15 and the sum of all the members of the chain, when the substance of formula I is a straight chain and when the compound of the formula I has a cyclic structure, the members of the ring being formed by X and groups ##EQU29## is not more than 50 with a cation which is a metal or ammonium ion.