Determination of cadmium at ultratrace levels by dispersive liquid-liquid microextraction and batch type hydride generation atomic absorption spectrometry

Abstract

This study describes the development of a dispersive liquid-liquid microextraction method for the extraction of cadmium and its determination by hydride generation atomic absorption spectrometry. The extraction method served as a clean-up of analyte from its matrix and also concentrated it to get lower detection limits. The hydride generation system was optimized to obtain high cadmium hydride generation efficiency and its transport to the quartz tube atomizer for atomization. Under the optimum experimental conditions, the limits of detection and quantification were 4.2ngL−1 and 14.1ngL−1, respectively. Sensitivity was enhanced about 10,000 folds if compared with conventional FAAS system. The calibration showed good linearity over a wide range and the low relative standard deviations indicated high precision for the extraction process and instrumental readings. The accuracy of the method was validated by the agreement of experimented results to the value of a wastewater certified reference material (EU-L-2). Appreciable recovery results were obtained for wastewater spiked at different concentrations.