Optimization of dispersive liquid–liquid microextraction by microvolume spectrophotometry method to determination of Celestine blue in water sample: response surface methodology

Abstract

Celestine blue (CB) was pre-concentrated by dispersive liquid–liquid microextraction (DLLME) and subsequently quantified with spectrophotometry in water samples and simultaneously correlation among response to variables like pH, disperser volume, extractor volume, ionic strong and extraction time was investigated by central composite design (CCD). The numerical optimization indicates that the optimum %ER (100.2%) achieved using 100µL of CHCl3, 800µL of ethanol, 0 mol L-1 NaCl, 5 min centrifugation and pH of 7. At optimal conditions method has linear dynamic range over 0.01-3.0 µg mL-1 with a pre-concentration and enrichment factor of 100 and 147.9, respectively. The limits of detection and quantification were 1.58 and 5.30 ng mL-1, respectively. Average recoveries for spiked samples in the interval of 92% and 100% which supply present DLLME method for CB determination in different waters and wastewaters samples, accordingly at prespecified optimum conditions. Abstract Celestine blue (CB) was pre-concentrated by dispersive liquid–liquid microextraction (DLLME) and subsequently quantified with spectrophotometry in water samples and simultaneously correlation among response to variables like pH, disperser volume, extractor volume, ionic strong and extraction time was investigated by central composite design (CCD). The numerical optimization indicates that the optimum %ER (100.2%) achieved using 100µL of CHCl3, 800µL of ethanol, 0 mol L-1 NaCl, 5 min centrifugation and pH of 7. At optimal conditions method has linear dynamic range over 0.01-3.0 µg mL-1 with a pre-concentration and enrichment factor of 100 and 147.9, respectively. The limits of detection and quantification were 1.58 and 5.30 ng mL-1, respectively. Average recoveries for spiked samples in the interval of 92% and 100% which supply present DLLME method for CB determination in different waters and wastewaters samples, accordingly at prespecified optimum conditions.