*2.3. Elemental Analyses*

The elemental composition of magnets was determined by inductively coupled plasma–optical emission spectroscopy (ICP-OES, iCAP 7000 Series, Thermo Scientific, Montréal, QC, Canada) equipped with a pneumatic concentric nebulizer. Table 2 presents the ICP-OES operating conditions. X-ray fluorescence (XRF) analyses were also used on some digestion residues to determine their elemental constituents. XRF analyses were performed in 3 replicates of 30 s for each filter (Na-S, Ni-Ag, Cr-Co, and Cl-V) using a MiniPal4 (Malvern Panalytical, Québec, QC, Canada).


