Assessment of dispersive liquid–liquid microextraction for the simultaneous extraction, preconcentration, and derivatization of H g 2+ and CH 3 H g + for further determination by GC – MS

This work reports the development of a dispersive liquid – liquid microextraction method for the simultaneous extraction, preconcentration, and derivatization of H g 2+ and CH 3 H g + species from water samples for further determination by GC – MS . Some parameters of the proposed method, such as volume and type of disperser and extraction solvent, and N a[ B ( C 6 H 5 ) 4 ] concentration were investigated using response surface methodology. Suitable recoveries were obtained using 80 μL C 2 C l 4 (as extraction solvent), 1000 μL ethanol (as disperser solvent), and 300 μL 2.1 mmol/L N a[ B ( C 6 H 5 ) 4 ] (as derivatizing agent). Accuracy was evaluated in terms of recovery and ranged from 87 to 99% with RSD values <7%. In addition, a certified reference material of water ( NIST 1641d) was analyzed and agreed with the certified value about 107% (for H g 2+ ), with RSD values <8.5%. LOD s were 0.3 and 0.2 μg/L, with enrichment factors of 112 and 115 for H g 2+ and CH 3 H g + , respectively. The optimized method was applied for the determination of H g 2+ and CH 3 H g + in tap, well, and lake water samples.