The interaction of tungsten(VI) with CV has been investigated in acetone-aqueous medium. The complex has been examined by solvent extraction-spectrophotometry method. In optimum conditions (pH 3; 30% acetone v/v) the ion-association complex of tungsten(VI) with CV was formed with ratio of 2 : 1, and it was extracted quantitatively one time with 5 mL toluene. In organic phase, the complex has maximum absorption at 599 nm with = x 104 -1 .cm-1 , and stable at least 2 hours after extraction. The complex is formed completely when concentration of CV is three times of that of tungsten(VI). Concentration of molybdenum(VI) up to 6 times of that of tungsten(VI) did not interfere.
