Microwave-assisted synthesis of antimony oxide nanoparticles for the determination of trace cadmium in mulberry leaf tea matrices by flame atomic absorption spectrophotometry

Abstract In this study, a rapid, sensitive and accurate analytical method was optimized for the determination of trace levels of cadmium (Cd) by flame atomic absorption spectrophotometry (FAAS) after antimony oxide nanoparticles (AO-NPs)-based dispersive solid-phase extraction (DSPE). The AO-NPs were synthesized with a specific microwave temperature program, and they exhibited high purity and good surface morphology, making them appropriate sorbent material for the preconcentration/separation of a heavy metal. All experimental parameters affecting the extraction efficiency were optimized univariately. Under the optimum operational conditions (35 mL sample volume, 0.75 mL of pH 8.0 buffer, 15 mg of sorbent, 5 s vortex and 100 µL of 1.0 M of HNO3), the limit of detection (LOD) and the limit of quantitation (LOQ) values were determined as 0.27 and 0.89 µg L −1 , respectively. Thanks to the developed method, a 164.8-fold improvement in the sensitivity of the conventional FAAS system was achieved. Reusability tests showed that the AO-NPs can be employed 5 times. The feasibility of the method was confirmed by recovery tests with mulberry leaf tea matrices, and good recovery results between 77.6 and 115.8% were obtained using the matrix matching calibration method.