Solutions of the optically active liquid anion exchanger named in the title were equilibrated with aqueous solutions of sodium mandelate. Racemic mandelate was used in some experiments, active mandelate in others. Some of the aqueous solutions also contained sodium benzenesulfonate. The analysis of the equilibrated phases yielded data from which the several anion-exchange selectivity coefficients were calculated, most importantly (+)-mandelate vs benzenesulfonate and (+)-mandelate vs (-)-mandelate. The results indicate that this liquid anion exchanger has important advantages over the analogous chloride in chloroform for the resolution of mandelate and other racemic anions. Some properties ofS-amine andS-ammonium benzenesulfonate are reported.