Ultrasound-assisted, ionic liquid-linked, dual-magnetic multiwall carbon nanotube microextraction combined with electrothermal atomic absorption spectrometry for simultaneous determination of cadmium and arsenic in food samples

Abstract

The facile, highly sensitive, rapid, and environment-friendly method, ultrasound-assisted, ionic liquid-linked, dual-magnetic multiwall carbon nanotube microextraction (USA-IL-LDMME), combined with electrothermal atomic absorption spectrometry (ETAAS), was proposed for simultaneous determination of cadmium and arsenic in food samples (cow milk, fish liver, and water samples). Sodium diethyldithiocarbamate trihydrate solution (NaDDTC·3H₂O) was used as the chelating agent. Influential factors such as solution pH, the amount of NaDDTC, ionic liquid volume, sample volume, and the amount of magnetic multiwall carbon nanotube were optimized. Applying all optimum conditions in the process, high enrichment factor of 403 and 398, linear range of 10–150 ng L⁻¹ and 10–100 ng L⁻¹, detection limits of 3 and 5 ng L⁻¹, and precision (RSD%, n = 7) of 2.8% and 3.2%, were obtained for cadmium and arsenic, respectively. The proposed procedure showed satisfactory results for analysis of cow milk, fish liver, tap water, and well water.