PURPOSE: To produce a resin adsorbing a pure extractant by cleaning an organic phosphorus compound extractant with an alkaline aqueous solution containing alcohol, separating the two phases and removing the water phase, admixing an adsorbing resin, stirring the three phase system of resin, extractant and aqueous solution to produce a two phase system of solid phase and water phase, removing the water phase and then cleaning and drying.

CONSTITUTION: A planed quantity of organic compound extractant is preparatively isolated and cleaned with an alkaline aqueous solution containing alcohol and then it is separated into two phases and the water phase is discarded. It is then admixed with an adsorbing resin and the three phase of adsorbing resin, extractant and alkaline aqueous solution 15 stirred for about three hours. Consequently, the oiliness disappears and a two phase system of solid phase and water phase is obtained. The water phase is discarded and the solid phase is cleaned with an alcoholic aqueous solution before being dries at about 110°C. Consequently, an acid organic phosphorus compound can be removed in the form of soap-like hydrophilic salt using an alkaline aqueous solution where the solubility to the water phase is enhanced by means of alcohol.