Spectrophotometric and liquid chromatographic determination of Zn(II), Ni(II), Fe(II), Co(II), and Cu(II) as metal chelates from vegetable and pharmaceutical samples using 3-hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridine carboxaldehyde-4-phenyl-3-thiosemicarbazone as derivatizing reagent

Abstract

A novel Schiff base chelating ligand 3-hydroxy-5-(hydroxymethyl)-2-methyl-4-Pyridine carboxaldehyde-4-phenyl-3-thiosemicarbazone (Pyridoxal-4-phenyl-3-thiosemicarbazone-PDPTSC) was synthetized and investigated for spectrophotometric and high performance liquid chromatographic (HPLC) separation and determination of Zn(II), Ni(II), Fe(II), Co(II), and Cu(II) as metal chelates on Microsorb C-18 (150 × 4.6 mm i.d, 5 µm) column. A good separation and elution of complexes was achieved isocratically with a mixture of methanol: water: acetonitrile: sodium acetate (1 mM) (65: 30: 4: 1 v/v/v/v) with a flow rate of 1 mL/min and UV detection was at 320 nm. The solvent extraction method was developed for simultaneous determination of metals with detection limits within 9.20–88.0 ng/mL. The developed method was applied for the quantitative determination of metal ions Fe(II), Zn(II) from pharmaceutical preparations, Surbex-Z, Polybion-Z, Fefol, and Fefolvit capsules with percentage recovery within (96.4–98.8%) (RSD% 1.86–4.28) and Co(II) and Cu(II) from vegetable samples carrot, potato, cucumber, and green peas with (RSD% 2.44–3.16) respectively.