Ampholyte and its use in separation processes

Claim 1

In a separation process selected from the group consisting of chromatographic processes and electrophoretic processes, including isoelectric focusing and isotachophoresis, in which process an ampholyte is used, the improvement which comprises using as said ampholyte a water-soluble ampholyte containing carboxyl groups and amino groups and comprising a mixture of amphoteric substances, said ampholyte comprising the reaction product obtained by reacting (a) at least two compounds selected from a group containing (A) amino acids, (B) hydroxylamine, (C) an amine of the formula ##STR8## wherein --R 1 is (i) hydrogen, or (ii) the group H 2 --N--(CH 2 ) n --, wherein n is an integer 2-6, or (iii) the group H 2 N--(CH 2 ) 3 --NH--(CH 2 ) 3 --R 2 and R 3 are the same or different and each representing either (1) hydrogen, (2) methyl, (3) ethyl, (4) hydroxyethyl, or (5) together with the intermediate nitrogen atom form an imidazolyl, morpholinyl- or piperazinyl group, and (D) di- and tripeptides said amino acids and said di- and tripeptides containing at least one nitrogen atom having one or two hydrogen atoms bound thereto and not containing aromatic groups other than imidazolyl and having molecular weight of at most 200, at least one of said at least two compounds being one which contains at least one carboxyl group, and/or salts of the aforementioned compounds, and (b) at least one bifunctional alkylating agent having the formula ##STR9## where X and Y are the same or different and each represents a halogen atom, the molar relationship between (b) and (a) being within the range of 1:2-9:10, in an aqueous alkaline medium.