Properties and applications of polyacrylacylisothiourea chelating fiber for preconcentration and separation of trace titanium, vanadium and bismuth

An ICP-OES method using a new polyacrylacylisothiourea chelating fiber to preconcentrate and separate trace Ti(IV), V(V) and Bi(III) ions from solution samples is established. The results show that 5-25 ng/ml of Ti or V and 50-250 ng/ml of Bi ions in 200-1000 ml of solution can be enriched quantitatively by 0.05 g of the fiber at pH 3 with recoveries over 97%. These ions can be desorbed quantitatively with 10 ml of 4 M HClO4. 100- to 1000-fold excesses of Fe(III), AI(III), Ca(II), Mg(II), Cu(II), Ni(II) and Mn(II) ions cause little interference. The chelating fiber stored for about 2 years can still be used repeatedly for preconcentration and separation of trace Ti, V and Bi ions from solution with above 95% recovery. The RSDs for enrichment and determination of 5 ng/ml of Ti or V and 50 ng/ml of Bi are in the range 2.5-2.8%. The recoveries of added standard in real waste waters and mineral samples are between 96 and 100%, and the concentration found for each ion in the mineral sample was in good agreement with that measured by ETAAS.