The effective membrane length in the contactor was 10 cm, and the effective outer (Ao = πdoLefε) and inner (Ai = πdi
Lefε) surface area of the membrane was 0.7 and 0.5 cm2 , respectively. The organic phase immobilized in the pores of the membrane was 0.16 mol dm−3 (5%) DEHPA in DHE. The volume of the organic phase was∼3 μL, calculated from the equation