Separation of metal bis(2-hydroxyethyl)dithiocarbamate complexes by micellar electrokinetic capillary chromatography

A method was developed for the separation of CdII, PbII, PtII, CoII, NiII, BiIII, CrII, CuII and HgII bis(2-hydroxyethyl)dithiocarbamate (HEDTC) complexes by micellar electrokinetic capillary chromatography. The complexes were formed by pre-capillary reaction of the metal ions with an excess of the ligand and then separated using a 100 mM borate buffer (pH 9.2) containing 4% methanol (v/v), 10 mM sodium dodecyl sulfate and 0.1 mM HEDTC, with detection at 254 nm. All the metal complexes, except PtII and PbII, were baseline resolved and separation was achieved in under 7 min. Detection limits were in the range 22 to 133 ppb.