Application of thiophene-2-carbaldehyde-modified mesoporous silica as a new sorbent for separation and preconcentration of palladium prior to inductively coupled plasma atomic emission spectrometric determination.

A new and efficient method was described for an easy synthesis of functionalized mesoporous silica (MCM-41) using thiophene-2-carbaldehyde. This new chemically bonded analytical reagent was used as an effective sorbent for the solid phase extraction of palladium(II) ion from aqueous solutions. Conditions for effective adsorption of trace levels of palladium concentration were optimized with respect to different experimental parameters in batch process. Thiourea solution could efficiently elute adsorbed palladium(II) ion from the surface of the sorbent which then was determined by inductively coupled plasma atomic emission spectrometer (ICP-AES). Common coexisting ions did not interfere with the separation and determination. The preconcentration factor was 100 (1ml elution volume) for a 100ml sample volume. The limit of detection of the proposed method is 0.2ngml(-1). The maximum sorption capacity of sorbent under optimum conditions has been found to be 5mg of palladium per gram of sorbent. The relative standard deviation under optimum conditions was 3.2% (n=10). Accuracy and application of the method was estimated by using test samples of natural and synthetic water spiked with different amounts of palladium(II) ion.