Dispersive Micro-Solid Phase Extraction of Selected Metals in Water and Food Samples Followed by ICP-OES Analysis: Method Development, Analysis of Real Samples and Greenness Evaluation

Multiwalled carbon nanotubes (MWCNTs) are well-known adsorbents because of their high surface area, layered and hollow architecture, hydrophobicity, and multiple and easily accessible adsorption sites. In this study, MWCNTs were used for dispersive micro-solid-phase extraction of various metal chelates in environmental and food samples. Different parameters such as concentration of the chelating reagent, the sorbent dosage, the extraction time, the desorption time, and the strength of the eluent were suitably optimized. Under the optimum extraction conditions, the proposed method demonstrated a good linear working range for all the analytes, with correlation coefficients above 0.9915. The limit of detection ranged from 0.02 to 0.21 μg/L. The inter-day and intra-day relative standard deviations were less than 2.5 %. The proposed method was used for the determination of selected metals in tap water, drinking water, cucumber, and tomato samples. In the end, GAPI tool was used to evaluate the greenness of the method.