Elution of Copper (II), Nickel(II), Cobalt(II) and Zinc (II) and the Separation of Nickel(II), Palladium(II) and Platinum(II) Complexes of Quinoxaline-2,3-Dithiol, Using Reserved Phase Ion-pair HPLC.

The anionic complexes of Cu(II), Ni(II), Co(II), Zn(11), Pd(Il) and Pt(ll) with quinoxaline-2,3-dithiol (qdt) were successfully eluted as ion-pair  with quaternary ammonium cations on the revened phase 1Uchrosorb RP-18 (ISO nun x 4.6 nun) column. The eluent UIed was ethanol:wala" (80:20) containing each in turn, tetrabutyl ammonium (TBA), tctraheptyl ammonium (fHA'1 and cetyltrimllthyl ammonium (CT A'1 •• their bromide salta in concentrations ransina (O.OS% to 0.2% wlv) at dilfereot pH.The Ni(ll) , Pd(I1) or Pt(ll)-qdt complexes were ICplIIaled &om Cu(ll) or Zn(11) or Co(U)-qdt complexes using THA+ ,or CTA+ at pH 8.4 ±. 0.1. The separation of Ni(ll), Pd(11) and Pt(ll) -qdt complexes was achieved using (fHA+) at pH 9.0:i: 0.1 with the cation salt concentration of 0.1% in ethanol: water (80:20) eluenl The detection limits were at ng levels per injection. 

J A W DALZIEL ,S A MEMON ,