“…The manifestation of metal atoms and their measurements play crucial roles in the study of environmental and biological effects resulting from heavy metal exposure. [1][2][3] Heavy metals are naturally existing metals in the Earth's crust. [4][5][6] Heavy metals are also considered trace elements because of their occurrence at trace levels Abbreviations: AAS, atomic absorption spectrometry; AFS, atomic fluorescence spectrometry; CoFe 2 O 4 , cobalt ferrite; ETAAS, electrothermal atomic absorption spectrometry; FeCl 2 Á4H 2 O, ferrous chloride tetrahydrate; FeCl 3 Á6H 2 O, ferric chloride hexahydrate; GFAAS, graphite furnace atomic absorption spectrometry; GO, graphene oxide; HCl, hydrochloric acid; HNO 3 , nitric acid; ICP-MS, including inductively coupled plasma mass spectrometry; ICP-OES, inductively coupled plasma optical emission spectrometry; L-Cys, L-Cysteine; MgFe 2 O 4 , magnesium ferrite; MNPs, magnetic nanoparticles; MOFs, magnetic metal-organic frameworks; MPOPs, magnetic-based porous organic polymers; MSPE, magnetic solid phase extraction; MWCNTs, multiwalled carbon nanotubes; PAMAM, polyamidoamine; PANI, polyaniline; PPy, polypyrrole; PS, polystyrene; SiO 2 , silicon dioxide; SPE, solid-phase extraction; UA-D-MSPE, ultrasound-assisted dispersive magnetic solid-phase extraction.…”