SEPARATION AND QUANTITATION OF SOME METAL-IONS BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY USING INSITU COMPLEXATION WITH (+/-)-TRANS-1,2-DIAMINECYCLOHEXANE-N,N,N',N'-TETRAACETIC ACID

(+/-)-trans-1,2-Diaminecyclohexane-N,N,N',N'-tetraacetic acid (DCTA) was used as a mobile phase complexing agent to separate and quantitate the metal ions Fe(II), Fe(III), Cr(VI), Cu(II), Ni(II), Co(II), Pb(II) and Hg(II) in reversed-phase high-performance liquid chromatography. Cations were separated as metal-DCTA complexes formed in the chromatographic system and detected by UV spectrophotometry. Selectivity depended on the methanol content of the mobile phase and the pH. The method was fairly sensitive and detection limits for some metal ions were established at the nanogram level.