NONCYCLIC POLYETHERS WITH TWO o-CARBOXYLPHENYL TERMINAL GROUPS EXHIBITING SELECTIVE TRANSPORT FOR ALKALINE EARTH METAL IONS THROUGH LIQUID MEMBRANES. EFFECT OF THE CONCENTRATION OF HYDROXIDE ION ON THE SELECTIVITY

Abstract
Three noncyclic polyethers containing o-carboxylphenyl groups as both end ones were synthesized. These synthetic carriers exhibit the selectivity for Ca++ or Ba++ in the competitive transport for Mg++, Ca++, and Ba++ in the source phase adjusted to initial pH 8.28 or 9.10 through liquid membranes. It was also found that the selective transport for alkaline earth metal ions can be changed by the concentration of hydroxide ion added.