Solid phase extraction of chromium(VI) from aqueous solutions by adsorption of its diphenylcarbazide complex on an Amberlite XAD-4 resin column

A method has been developed for the solid phase extraction of chromium(VI) based on the adsorption of its diphenylcarbazide complex on an Amberlite XAD-4 resin column. The influence of acidity, stability of the column, sample volume, flow rate and interfering ions were studied in detail. The adsorbed complex could be eluted using acetone-sulfuric acid mixture and the concentration of chromium was determined using visible spectrophotometry. A detection limit of 6 mu g L-1 could be achieved. A preconcentration factor of 27 could be obtained for 400 mL sample volume. The validity of the method was checked in spiked water samples and electroplating wastewater. (c) 2007 Elsevier B.V. All rights reserved.