Systematic studies on adsorption of 11 trace heavy metals on thiol cotton fiber Original Research Article

The modified thiol cotton fiber (TCF) can quantitatively adsorb, at least the ions of 11 trace heavy metals in solution with adsorption order: Bi(III)≈Sn(II)>Ag(I)>Cu(II)>In(III)>Pb(II)>Cd(II)>Zn(II)>Co(II)≈Ni(II)>Tl(I) and a saturation adsorption quantity of ca. 0.3 mmol g−1. For a column with 0.1 g of TCF and a flow rate of 10–20 ml min−1, it can quantitatively adsorb the trace heavy metals and quantitative desorption of the elements can be realized by elution with 2–3 ml of 0.01–2.0 mol l−1 HCl. TCF eluted by dilute HCl can be reused many times and the adsorption rate is not decreased. The coexistence of metals, the complexing reagents and the organic compounds in the solution does not interfere with the quantitative adsorption of most of the trace metals on TCF; some oxidizing reagents obviously interfere with the preconcentration of a sample with a big volume of water, which can be effectively pre-eliminated by adding a suitable amount of some reducing agent. The experimental results show that TCF possesses excellent adsorption and desorption properties and is of great value to the application of the enrichment, the separation and the analyses of the trace elements.