Magnetic solid‐phase extraction of nickel(II) as the 2‐(5‐bromo‐2‐pyridilazo)‐5‐(diethylamino)phenol chelate on magnetite@methacrylic ester copolymer prior to high‐resolution–continuum source flame atomic absorption spectrometric detection

Abstract A Fe3O4@ Diaion HP‐2MG resin was used for separation-preconcentration and determination of trace Ni(II) as the 2‐(5‐bromo‐2‐pyridilazo)‐5‐(diethylamino)phenol (PADAP) chelate. Nickel determination was performed by high‐resolution–continuum source flame atomic absorption spectrometry (HR-CS FAAS). Among the parameters affecting the recoveries of Ni(II) on the Fe3O4@ Diaion HP-2MG, the pH, resin mass, and sample volume were optimized. The influence of matrix ions upon the analyte recovery was evaluated and the tolerance limit was determined for common ions. The Fe3O4@ Diaion HP-2MG resin was used 15 times without any degradation in performance. The limit of detection, the limit of quantification, and preconcentration factor were 15.0 µg L−1, 49.0 µg L−1, and 100 respectively. The accuracy of the developed method was validated by the analyzing certified reference materials (NIST 1573a tomato leaves and TMDA-64.3 fortified water). The developed procedure was applied to natural water and food samples.