Dispersive Solid Phase Extraction Combined by Dispersive Liquid- Liquid Microextraction for Preconcentration of Brilliant Green from Fish and Seawater Samples and its Determination by Spectrophotometry

Abstract

A highly sensitive, simple and speed technique was employed for the determination of brilliant green in fish (Sphyraena jello) and seawater samples by visible spectrophotometry after its extraction and enrichment with chitosan- zinc oxide nanoparticle coupled with dispersive liquid- liquid microextraction. Ultra-trace concentrations of brilliant green were dispersed to organic phase in DLLME method after adding of dispersive solvent and chitosan- zinc oxide nanoparticles. The experimental factors such as amount of chitosan- zinc oxide nanoparticles, concentration of Triton X- 114, type of volume of extraction and dispersive solvents, extraction time, rate and time of centrifugation, volume of sample and pH were investigated to order to enhance of the extraction efficiency. Under optimum extraction condition, volume of chloroform (as extraction solvent) and methanol (as dispersive solvent) were 100.0 µL and 550.0 µL, respectively; amount of chitosan- zinc oxide nanoparticles was 15.0 mg; time of extraction was 4.0 min; rate and time of centrifugation were 3000.0 rpm and 8.0 min, respectively, volume of sample was 8.0 mL, and pH of sample solution was 4.0. After optimizing of the microextraction conditions and instrumental factors, an enrichment factor of 169.0 was achieved. The analytical curve )absorbance vs. concentration( was linear over the range 1.0-200.0 µg/L of brilliant green. The limit of detection and relative standard deviation were 0.3 µg/L and < 6.1 %, respectively. The protocol was successfully employed to the determination of brilliant green in seawater of Chabahar Bay and fish (Sphyraena jello) samples.