the metal ions tested included six divalent cations ( ca ( 2+ ) , mg ( 2+ ) , sr ( 2+ ) , ba ( 2+ ) , co ( 2+ ) , and ni ( 2+ ) ) and three trivalent cations ( la ( 3+ ) , y ( 3+ ) and eu ( 3+ ) ) .2 .
C0007448
divalent cations
C0007447
cations