Distribution coefficients (Henderson-Kracek, Khlopin), D-2/1, of trace amounts of Ni2+, Mg2+, CU2+, Zn2+, Mn2+, Cd2+, Ca2+, and Sr2+ have been determined during crystallization of Co(CH3COO)(2)center dot 4H(2)O. Their dependencies on some properties of cocrystallizing salts (acetate hydrates) as well as cocrystallizing ions (M2+) have been analyzed. The D-2/1 values are comprised in the range of 0.004(D-Sr)-3.3(D-Ni) but most of them are less than 0.06. This indicates that most of investigated M2+ ions may be effectively removed in preparation of high-purity cobalt(II) sales. M2+ ions for which vertical bar r(Co2+) -r(M2+)vertical bar/r(Co2)+ > 0.05, cocrystallize Co(CH3COO)(2)center dot 4H(2)O only in slight degree than ions of electron configuration d(0) or d(10). (c) 2006 Elsevier B.V. All rights reserved.