A New Dispersive Liquid-Liquid Microextraction Method Followed by Direct GFAAS Determination Optimized with Experimental Design and Response Surface Methodology for Determination of Ag(I) in Water Samples

In this research, a rapid, reliable and selective dispersive liquid-liquid microextraction (DLLME) followed by direct injection of microdroplet to graphite furnace atomic absorption spectrometry (GF-AAS) method for the determination of ultra-trace amounts of Ag(I) was developed. Effect of the important expenmental parameters on the extraction efficiency of Ag(I) was investigated using response surface methodology (RSM) by performing a central composite design (CCD). A newly synthesized Calixarene (mesotetraspirocyclohexylcalix[4]pyrrole, TSCC4P) was utilized as the chelating agent. The optimal expenmental condition was obtained as sample volume: 5 ml, dispersive solvent type: methanol, dispersive solvent volume: 715 mu l, extracting solvent: 1,2-dichlorobenzene, volume of extracting solvent: 25 mu l, amount of TSCC4P: 127.1 pg, and pH of sample solution: 6.5. Under the optimum conditions Ag(I) ions were extracted into a fine sedimented microdroplet, which 10 mu l of it was directly injected into GF-AAS system. The calibration graph was linear over the range of 0.1-10.0 mu g ml(-1) with a detection limit (S/N = 3) of 0.02 ng m(-"). TThe relative standard deviation (RSD%) for ten replicated determinations of 10 ng m(-11) Ag(I) was . 1.% The enrichment factor and extraction recovery were found to be 292 and 96%, respectivel.y The proposed DLLME-GF-AAS method was successfully applied to the extraction and determination of Ag(I) ionsinm different real water sample.s