Inert sep me 2

Three commercially available aminocarboxylic acid-type chelating resins, Presep PolyChelate (250 mg packed into a 3 mL solid-phase extraction cartridge, FUJIFILM Wako Pure Chemical), NOBIAS Chelate PA-1 (250 mg packed into a 6 mL cartridge, Hitachi High-Tech Fielding), and InertSep ME-2 (250 mg packed into a 6 mL cartridge, GL Sciences), were used. The deionized water used for all investigations was prepared using a Merck Milli-Q Gradient. An ICP multielement standard XVI (As, Be, Ca, Cd, Co, Cr, Cu, Fe, Li, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, Ti, Tl, V, Zn; 100 mg L -1 each; Merck) and a Y standard stock solution (1000 mg L -1 , Kanto Chemical) were employed as standard solutions; these solutions were diluted appropriately before use. Certified reference materials, EnviroMAT Ground Water (ES-L-1) and EnviroMAT Waste Water (EU-L-3), which were purchased from SCP Science, were used to validate the solid-phase extraction with internal standardization. The other reagents used were of guaranteed or analytical reagent grade.