Trace determination of cadmium in rice samples using solidified floating organic drop microextraction based on vesicular supramolecular solvent followed by flow-injection analysis–flame atomic absorption spectrometry

Abstract

In this work, a solidified floating organic drop microextraction was developed based on a vesicular supramolecular solvent consisting of decanoic acid and quaternary ammonium. The method was used for preconcentration of trace amount of cadmium in different rice samples followed by flow-injection analysis–flame atomic absorption spectrometry. Several parameters affecting the extraction efficiency including pH, concentration of 1-(2-pyridylazo)-2-naphthol as the chelating agent, sample and extraction solvent volume, stirring rate, extraction time, salt effect, and interfering ions were investigated and optimized. Under the optimum conditions, a preconcentration factor of 84 was achieved. LOD and LOQ were found to be 0.09 and 0.31 µg L−1, respectively. The calibration curve was linear within the range of 5.0–700 µg L−1 (r2 > 0.9978). Intra- and inter-day precisions (RSD% n = 3) were estimated 2.7 and 3.9% at the concentration of 20 µg L−1, respectively. The accuracy of the method was successfully validated by analysis of an SRM-1643f standard reference material. Relative recoveries were achieved within the range of 93–107% elucidating suitability of the method for determination of cadmium in rice samples.