Chemistry Research and Practice
- ISSN: 3065-906X
S. Echioda, N. A. Idongesit, Salisu Salisu and Adepeju Oluwabunmi Ogunieye
In this work, synthesis, characterization and spectrophotometric study of glutaraldehydiphenyl hydrazone (GDP), a chromogenic reagent for determination of selected heavy metals in water and soil samples has been carried out. The results obtained showed product yield of 79.0%, nitrogen content of 18.91% and melting points of 129-131ºC. Infrared spectra data obtained showed absorptions bands at regions around 3492.5, 3451 for –NHR groups and stretches at 3085 and 1604 for -CH and C=N respectively. The nuclear magnetic resonance (13C-NMR) spectrum showed peaks around 111.0-141.0 for aromatic carbons, 129.3ppm for cyano carbon atom and 40.0, 39.2 and 31.7ppm for three methylene carbons. The 1HNMR spectrum revealed peaks at 1.64-1.69 ppm for multiplet –CH2 - protons, 2.214-2.386 ppm for quartet –CH2 - protons, 7.331-7.345 ppm for -CH protons, 7.015 ppm for –NH signal and 6.59-7.34 ppm for aromatic protons. The spectral analysis of the glutaraldehydiphenyl hydrazone complexes revealed wavelength ranging between 360.0 (Cr) to 395.0 nm for (Pb and as) as maximum absorption at a working pH of 6.5 to 7.5 at 37°C. The reagent showed a molar absorptivities (L mol-1 cm-1) ranging from 2.213 x 104 (Pb) to 2.460 x 104 (As), a mole ratio of metal to ligand of 2:1, detection limits (µg/g) ranging from 0.3432 (As) to 0.5250 (Pb) and the metal-ligand complex was stable for 0-48 hours. Additionally, the compounds Beer’s law validity ranges from 0.001 to 100 (mgL-1). The spectrophotometric results were compared with atomic absorption spectroscopy results and the results were satisfactory with good precision for the GDH method.