Pyridine-functionalized mesoporous silica as an adsorbent material for the determination of nickel and lead in vegetables grown in close proximity by electrothermal atomic adsorption spectroscopy

► Pyridine-functionalized mesoporous silica is an effective solid-phase material. ► Nickel and lead in vegetables samples can be determined at ng mL−1 levels. ► Trace amounts of nickel and lead in vegetable can be determined simultaneously. ► Extraction of nickel or lead by mesoporous silica at pH of 7 or 8 is selective.