Ferrofluid-based dispersive solid phase extraction of palladium

A new mode of dispersive solid phase extraction based on ferrofluid has been developed. In this method, an appropriate amount of ferrofluid is injected rapidly into the aqueous sample by a syringe. Since the sorbent is highly dispersed in the aqueous phase, extraction can be achieved within a few seconds. The ferrofluid can be attracted by a magnet and no centrifugation step is needed for phase separation. Palladium was used as a model compound in the development and evaluation of the extraction procedure in combination with flame atomic absorption spectrometry. The experimental parameters (pH, DDTC concentration, type and concentration of eluent, the amount of adsorbent, extraction time, and the effect of interfering ions) were investigated in detail. Under the optimized conditions, the calibration graph was linear over the range of 1–100 μg L−1 and relative standard deviation of 3.3% at 0.1 μg mL−1 was obtained (n=7). The limit of detection and enrichment factor (EF) was obtained to be 0.35 μg L−1 and 267, respectively. The maximum adsorption capacity of the adsorbent at optimum conditions was found to be 24.6 mg g−1 for Pd(II). The method was validated using certified reference material, and has been applied for the determination of trace Pd(II) in actual samples with satisfactory results.