SEPARATION OF METAL-IONS AND THE DETERMIN ATION OF CALCIUM AND MAGNESIUM-IONS WITH '-DI(2-HYDROXYBENZYL)ETHYLENEDIAMINE-N,N'-DIACETIC ACID BY HIGH-PERFORMANCE CAPILLARY ELECTROPHORESIS

The capillary electrophoresis study was carried out by using HBED as a chelating and coloring agent. The title compound HBED(H4Y) reacts wit h divalent (M(2+)) and trivalent metal ions (M(3+)) to form chelate an ions MY(2-) and MY(-), respectively. Eleven divalent metal ions and th ree trivalent metal ions were detected as peaks at pH 9.3. When a carr ier containing 2X10(-3) M HBED (pH 10.5) and sample solutions containi ng 1X10(-4) M HBED were used, the mobilities of the metal ions (absolu te value) increased in the following order: Co2+(Co3+)(2.05)<Mn2+(2.10 )<Al3+(2.12)<Fe3+(2.15)< 3.21)<Ca2+(3.26)<Ni2+(3.34)<CU2+(3.42)<Zn2+(3 .52)< Pd2+(3.60)<HBED(3.74). Most of the metal ions form stable chelat es at about pH 10. HBED chelates absorb UV light strongly at longer wa velenghs near to 294 nm, compared with EDTA chelates; highly sensitive detection of metal ions could be achieved with HBED. The proposed met hod with HBED was applied to the determination of calcium and magnesiu m ions in river water and serum samples.