Laser induced resonance energy transfer - A novel approach towards achieving high sensitivity in capillary electrophoresis Part B: Applications for environmental testing

Capillary electrophoresis with laser induced resonance energy transfer detection is used for direct determination of ethylenediamine tetraacetic acid (EDTA), 1,2-diaminopropane-N,N,N',N'-tetraacetic acid (DPTA) and (+)-trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (DCTA) in aqueous samples. The method involves CZE separation of salicylate-Tb-EDTA, salicylate-Tb-DPTA and salicylate-Tb-DCTA ternary complexes at alkaline pH. The highly efficient transfer of energy from salicylate to terbium in these complexes facilitated a sensitive detection. Detection limits in the 1 · 10^-7 M range are easily achieved. A 325 nm HeCd laser is used for excitation and terbium luminescence is monitored at 547 nm. The potential application of this method in analyzing these acids in a complex radioactive waste is discussed.