Electrochemical Detection of 4-Nitrophenol

All the reagents and chemicals
were of analytical grade and used without further purification. These
include urea (CO(NH₂)₂), ammonium sulfate ((NH₄)₂SO₄), absolute ethanol (C₂H₅OH, 97%), sulfuric acid (H₂SO₄), sodium hydroxide (NaOH), ammonium hydroxide (NH₄OH),
zirconia oxychloride hydrated (ZrOCl₂·8H₂O), potassium ferric-hexa-cyanide (K₃Fe(CN)₆), dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), potassium
chloride (KCl), and hydrochloric acid (HCl, 98%). 4-nitrophenol (C₆H₅NO₃) and alumina (Al₂O₃) were obtained from Sigma-Aldrich and monosodium hydrogen
phosphate (NaH₂PO₄) and disodium hydrogen phosphate
(Na₂HPO₄) from Samir Tech-Chem, India. 4-NP
was selected as the target contaminant and used as supplied. A potentiostat
(Autolab Ivium Technologies B V De Zaale 11 5612 AJ Eindhoven, Netherlands)
coupled with a personal computer was used for electrochemical studies.^{3 (link)}