Systematic studies on adsorption of trace elements Pt, Pd, Au, Se, Te, As, Hg, Sb on thiol cotton fiber Original Research Article

The modified thiol cotton fiber (TCF) can quantitatively adsorb Pt(II), Pd(II), Au(III), Se(IV), Te(IV), As(III), Hg(II) and Sb(III) strongly in addition to its adsorption of Bi(III), Sn(II), Ag(I), Cu(II), In(III), Pb(II), Cd(II), Zn(II), Co(II), Ni(II), and Tl(I). In a HCl solution, the adsorption order for the eight elements is Pt(II)≈Pd(II)>Au(III)≈Se(IV)>Te(IV)>As(III)>Hg(II)>Sb(III). The adsorption capability of TCF for these eight ions depends on the affinity of SH for the ions and complexing reactions in solution. The extent of adsorption of TCF for the ions depends on the varieties of elements, the oxidation states and species of the elements, and the acidity and the components of the solution. In general, TCF only adsorbs ions in their lower oxidation states. The saturation adsorption of TCF for the eight elements is 10–70 mg g−1. For a column with 0.1 g of TCF, except for As(III) and Se(IV) the quantitative adsorption flow rate for the other six elements is 10–30 ml min−1. The ions adsorbed on TCF can be separated and quantitatively desorbed with 2–3 ml of a desorption reagent under suitable conditions. The experiments showed that most matrix elements, complexing reagents and organic compounds do not interfere with the quantitative adsorption of the trace elements on TCF. The recoveries of the standards at the μg l−1 level of the eight elements added to four types of natural water samples are all >85%.