Application of Dispersive Liquid-Liquid Microextraction in Separation and Preconcentration of Silver prior its Determination by Flame Atomic Absorption Spectrometry

摘要

A simple, sensitive, and rapid dispersive liquid-liquid microextraction (DLLME) method is developed for the preconcentration of silver ions prior to determination by flame atomic absorption spectrometry (FAAS). In this work, 1-phenyl-1,2-propanedione-2-oximethiosemicarbazone (PPDOT), chloroform, and methanol are used as the complexing agent, extraction solvent, and disperser solvent, respectively. The effects of different analytical parameters on the complex formation and the extraction efficiency are investigated and optimized. The effects of interfering ions on the determination of silver(Ⅰ) are also examined. Under the optimized conditions, a linear calibration curve was achieved in the range of 0.60-120.0 μg L~(-1), with the detection limit of 0.61 μg L~(-1). The pre-concentration factor calculated as the ratio of the slopes of the calibration graphs with and without the pre-concentration was 35.5. The relative standard deviations (RSDs) for the silver(Ⅰ) determinations were below 3 %. The proposed separation procedure was successfully applied to the determination of silver(Ⅰ) in natural water and photographic film samples with satisfactory results (recoveries ＞ 95 %).