Trace monitoring of silver ions in food and water samples by flame atomic absorption spectrophotometry after preconcentration with solvent-assisted dispersive solid phase extraction

Abstract

In this research, a new sample treatment technique termed solvent-assisted dispersive solid phase extraction (SADSPE) was developed. The new method was based on the dispersion of the sorbent into the sample to maximize the contact surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by injecting a mixture solution of the sorbent and disperser solvent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy solution resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. After extraction, the cloudy solution was centrifuged and the enriched analytes in the sediment phase dissolved in ethanol and determined by FAAS. Under the optimized conditions, the detection limit for silver ions was 0.8 μg L(-1). The relative standard deviations for six separate extraction experiments for determination of 5 and 200 μg L(-1) of silver ions was 3.4 and 3.1 %. The preconcentration factor was found to be 61.7. SADSPE was successfully applied for trace determination of silver ions in water and food samples.