Solid-phase extraction of gold(III) using a fibrous adsorbent immobilizing pentaethylenehexamine

Pentaethylenehexamine was immobilized on acrylic fiber in 2-propanol/water at 100°C for 15 h. The obtained fibrous adsorbent was able to adsorb gold(III) effectively at pH 1. The adsorption capacity for gold(III) was 2.5±0.1 mmol g⁻¹ (mean±standard deviation, n = 3). The adsorption was rapid; 80% of gold(III) was adsorbed even at a flow rate of 63 mL min⁻¹when 0.10 g of the fibrous adsorbent and 100 mL of a solution containing 5.1×10⁻² mmol L⁻¹ of gold(III) at pH 1 were used. The adsorbed gold(III) could be quantitatively desorbed using 1 mol L⁻¹ hydrohloric acid containing 0.1 mol L⁻¹ thiourea. The fibrous adsorbent barely adsorbed 21 kinds of elements, including alkaline earth elements, such as calcium(II), and transition metal elements, such as manganese(II) and iron(III), at pH 1. The solid-phase extraction using the fibrous adsorbent was applicable to the separation of gold(III) in a real wastewater.