Detection of copper in boiled water samples from traditional coffee pots by applying deep eutectic solvent-assisted reduced graphene oxide-coated magnetic nanocomposite-based microextraction strategy

This study presents the use of a magnetic nanofluid (MNF) comprising of deep eutectic solvent (DES) and reduced graphene oxide-coated magnetic nanocomposite (RGO@MNC) to preconcentrate copper from water brewed in a traditional coffee pot for determination by flame atomic absorption spectrometry (FAAS). The DES served as a carrier fluid to enhance the dispersion of RGO@MNC in aqueous solution. Significant parameters of the method were optimized to enhance the extraction efficiency. Optimum parameter variables were used to validate the method, recording a detection limit of 6.8 ng mL-1, a quantification limit of 22.7 ng mL-1, and a percent relative standard deviation (RSD%) of 6.2. The method exhibited good linearity in a wide concentration range of 20-500 ng mL-1. Water boiled in the traditional coffee pot was spiked at 60, 120, 225, and 300 ng mL-1, and the high recovery results demonstrated the viability of the method in wide concentration range.