Solid phase extraction of ultra traces mercury (II) using octadecyl silica membrane disks modified by 1,3-bis(2-ethoxyphenyl)triazene (EPT) ligand and determination by cold vapor atomic absorption spectrometry

► A highly efficient preconcentration of Hg(II) ions in water samples was achievable by the SPE modified disk and (CV-AAS) technique. ► The newly synthesized 1,3-bis(2-ethoxyphenyl)triazene ligand (EPT) was used as a disk modifier. ► Solution studies with EPT and different metal ions including Hg(II) were conducted. ► High improvement (74) and preconcentration (380) factors, wide linear range, low detection limit (10.6 ng L−1) and RSD (1.1%) were achieved.