JOURNAL OF AOAC INTERNATIONAL, vol.99, no.4, pp.1058-1065, 2016 (SCI-Expanded)
A new and simple dispersive liquid liquid simultaneous microextraction procedure was developed for the rapid separation and simultaneous extraction/preconcentration of Cd(II) and Ni(II) at ultratrace amounts. Microextraction of the analytes was carried out in the presence of 2-methyl-5-[(Z)-pyridin-4-yldiazenyl]quinolin-8-ol as the chelating reagent. Chloroform and ethanol were used as the extraction and dispersive solvents. Various parameters that influence the microextraction procedure's efficiency such as pH, centrifugation rate and time, reagent concentration, and sampling volume on the recovery of analytes were examined. The calibration curves were linear in the range of 0.01-1.25 and 0.075-5 mg/L with LODs of 0.25 and 0.84 mu g/L, and with a preconcentration factor of 94, for Cd(II) and Ni(II), respectively. Precision was >1.0%. The accuracy of the method was confirmed by analyzing the Certified Standard Reference Material (CWW-TMD: Certified wastewater-Trace metals, wastewater). The results show that the dispersive liquid liquid simultaneous microextraction pretreatment is a sensitive, rapid, simple, green, and safe method for the separation/preconcentration of cadmium and nickel.