SEPARATION OF BORON ISOTOPES BY ION-EXCHANGE CHROMATOGRAPHY

Separation of the isotopes of boron by ion exchange chromatography has been studied using mannitol as a complexing reagent for boric acid. Quadratic regression analysis shows that the pH and the acidity constant (pK(a)) of 0.1 M boric acid can be related to the concentration of mannitol, [m], by the relations: pH = 5.365 - 9.270 [m] + 11.869 [m]2 pK(a) = 9.124 - 13.684 [m] + 14.482 [m]2 for 0.0 less-than-or-equal-to [m] less-than-or-equal-to 0.5 The values of the single stage separation factor for B-10-B-11 exchange are found to be 1.0173 and 1.0194 for 0.1 M boric acid in presence of 0.1 M and 0.2 M mannitol. The value of separation factor for 0.2 M mannitol is similar to the one obtained by reduced partition function ratios for the reaction, B-10(OH)3 + B-11(OH)4- reversible B-10(OH)4- + B-11(OH)3, indicating thereby that B-10 is enriched in the anionic species. The effects of mannitol concentration on the breakthrough profiles and separation factor have been studied. The effect of concentration of boric acid (at constant mannitol concentration of 0.3 M) has also been studied for the resin used. The advantages of mannitol over glycerol are discussed.