Development of a green effervescence-assisted dispersive liquid–liquid microextraction method using a home-made tablet disperser for trace analysis of Cd(II) and Pb(II)

Abstract

ABSTRACTAn analytical approach for the determination of trace amounts of Cd(II) and Pb(II) has been developed using a home-made tablet-based effervescence-assisted dispersive liquid–liquid microextraction (DLLME) method which was performed in a narrow-bore tube, followed by flame atomic absorption spectrometry. In this method, a mixture of tartaric acid, sodium bicarbonate and NaCl was used to make the disperser tablet. Then, microlitre level of an extraction solvent was added in the tablet, and then, it was released into a narrow-bore tube containing sample solution and a complexing agent. An acid–base reaction immediately occurred between tartaric acid and sodium bicarbonate, and the produced CO2 led to the dispersion of the extraction solvent into the solution as tiny droplets and subsequent extraction of the analytes. The method made possible the determination of Cd(II) and Pb(II) in the ranges of 0.1–10 and 1.0–20 µg L−1, respectively. The limits of detection were obtained 0.43 and 0.05 µg L−1 for Pb(II) and Cd(II), respectively. The limits of quantifications were 0.80 and 0.09 µg L−1 for Pb(II) and Cd(II), respectively. Repeatability of the method, which is expressed as relative standard deviation, was obtained 3.1% (n = 6, C = 2 µg L−1) and 1.3% (n = 6, C = 0.2 µg L−1) for Pb(II) and Cd(II), respectively. The accuracy of the developed method was verified by analysing a certified reference material, namely SPS-WW2 Batch 108. Relative recoveries (84–107%, obtained at three fortification levels) confirmed the usefulness of the method for analysis of the analytes in the environmental water samples and fruit juices. The method was shown to be fast, reliable and environmentally friendly with low organic solvent consumption.