Speciation of as(III), as(V), total inorganic arsenic and total arsenic in sport and bodybuilding supplements using new nanocomposite for dispersive magnetic micro-solid phase extraction followed by GFAAS analysis

A novel microalgae-derived magnetic nanocomposite was engineered for As speciation. • First application of a Chlorella-based sorbent to sports supplements. • Ultra-trace arsenic determination achieved with 0.05 μg kg −1 detection limit. • Speciation revealed arsenic occurs mainly in less-toxic organic forms. Reliable speciation of inorganic arsenic in complex dietary supplements remains analytically challenging because of severe matrix interferences and the low concentrations of toxic arsenic species. In this study, a novel magnetic nanocomposite (ZnO–ZnFe₂O₄@CHL-MNCs) derived from Chlorella biomass was synthesized and employed as an efficient sorbent for ultrasound-assisted dispersive magnetic micro-solid phase extraction (UA-D-μ-SPE) prior to graphite furnace atomic absorption spectrometry (GFAAS). The synergistic integration of ZnO, ZnFe₂O₄, and the porous biomass-derived carbon matrix provided abundant active adsorption sites, high magnetic responsiveness, and rapid phase separation, resulting in efficient enrichment of inorganic arsenic species. Under the optimized conditions, the proposed method exhibited a linear range of 0.15–100 μg kg −1 (R 2  = 0.994), a limit of detection of 0.05 μg kg −1 , an enrichment factor of 163, and satisfactory intra- and inter-day precisions of 4.1% and 6.3%, respectively. The method was successfully validated using a certified reference material (NMIJ CRM 7503a) and subsequently applied to the determination of As(III), As(V), total inorganic arsenic, and total arsenic in commercial sport and bodybuilding supplements. Spike recoveries ranging from 92.7% to 106.7% confirmed negligible matrix effects and excellent analytical accuracy. The proposed strategy offers a rapid, sensitive, and environmentally friendly approach for arsenic speciation in complex food matrices and represents a promising alternative for routine food safety monitoring. Download: Download high-res image (240KB) Download: Download full-size image