ACETOHYDROXAMATE RESIN AS COLUMN PACKING FOR ION CHROMATOGRAPHY

A chelating resin with acetohydroxamate functional groups was synthesized and used as the stationary phase in ion chromatography for the determination of copper. As the reaction mechanism was mainly complexation, the coordination behavior of the synthesized resin toward Cu(II) was studied by means of EPR, IR and electronic spectrometry and potentiometry. The kinetic study shows that the resin is suitable for use in ion chromatography. We employed a resin column 250 mm long by 3 mm I.D. in conjunction with a mixture of hydrochloric acid and acetone as mobile phase for the determination of Cu(II). Detection of the chromatography system was carried out via post-column derivatisation of the column effluent with PAR at 520 nm. The detection limit is 0.22 ppm, and the relationship was linear in the range 0.25-1.20 ppm. We investigated the effect of other metal ions, As(V), Cd(II), Cr(III), Hg(II), Ni(II), Pb(II) and Zn(II), or foreign ligands, EDTA, ascorbic acid, humic acid or sodium chloride on the determination of Cu(II) ion. A concentration column packed with acetohydroxamate resin combined with the above separation system was also used to determine of copper ion; the dynamic range is 2-15 ppb and the detection limit is 0.70 ppb. The proposed system was applied to the analysis of Cu(II) in sea water.