Analysis of ions present at low concentrations in solutions containing

Abstract

A method of selectively and quantitatively removing and concentrating at least one selected ion from a multiple ion solution in which other ions are present is disclosed. The method comprises (a) bringing a complexing agent for the selected ion(s) into contact with the multiple ion solution to remove and concentrate selected ion(s) from the multiple ion solution, wherein the complexing agent is selected from the group of macrocyclic compounds having at least four --A--CH.sub.2 --CH.sub.2 -- groups in which A is selected from O, O--CH.sub.2, S, S--CH.sub.2, N--R and N--R--CH.sub.2 in which R is selected from H, lower alkyl and benzyl, with the macrocyclic compounds further having a hydrocarbon side chain having an end group ##STR1## in which X is selected from the group consisting of lower alkyl, benzyl, phenyl, halogen, O--CH.sub.3, O--C.sub.2 H.sub.5 and O--M, wherein M is selected from the group consisting of sand, silica gel, glass, glass fibers, alumina, zirconia, titania and nickel oxide; (b) removing the multiple ion solution from which the complexing agent has removed the selected ion(s) from the complexing agent having the selected ion(s) complexed therewith; (c) bringing the complexing agent complexed with selected ion(s) into contact with a receiving liquid to break the complex and remove the selected and concentrated ion(s) from the complexing agent; and (d) determining the concentration of selected ion(s) in the receiving liquid from which the concentration of selected ion(s) in the multiple ion solution can be calculated.