Spectrophotometric Determination of Aminophenol Isomers Via Oxidative Coupling Reaction with 4-Aminoantipyrine

Al-Luhaiby, Reem Abed Ahmed; Alenizzi, Mohammed

doi:10.33899/edusj.2020.126543.1041

	Spectrophotometric Determination of Aminophenol Isomers Via Oxidative Coupling Reaction with 4-Aminoantipyrine
Journal of Education and Science
Article 6, Volume 29, Issue 3, 2020, Pages 68-84 PDF (767.74 K)
Document Type: Research Paper
DOI: 10.33899/edusj.2020.126543.1041
Authors
Reem Abed Ahmed Al-Luhaiby^* ¹; Mohammed Alenizzi²
¹Department of chemistry, College of Education for Girls, Mosul University, Mosul, Iraq
²Department of Chemistry, Education College for Girls, University of Mosul
Abstract
A spectrophotometric method has been developed for the determination of aminophenol isomers (o-aminophenol, m-aminophenol and p-aminophenol). The method is based on oxidative coupling reaction of these compounds with 4-aminoantipyrine (4-AAP) in the presence of cupper sulphate as oxidizing agent in alkaine medium forming a reddish brown colour. The products show maximum absorption at 440 nm, 480 nm and 445 nm for o-aminophenol, m-aminophenol and p-aminophenol respectively. The molar absorptivities are 8.632×103 ,9.33×103 and 9.1449×103 l.mol-1.cm-1 for concentrations obeyed Beer’s law in the range 1-20, 1-24 and 1-7 μg.ml-1 for the above compounds respectively. The average recovery was ranged between 98.38% and 101.01% with relative standard deviation < 1.6 for all the studied compounds. The 4-AAP products were formed in the ratio of 1:2 aminophenol isomers : 4-AAP. The stability constant of the products was 7.4 ×108, 3.27×108 and 9.94×107 l2.mol-2 for o-aminophenol, m-aminophenol and p-aminophenol products respectively indicating the good stability of these products.
Keywords
: Oxidative coupling,,; ,،,؛Spectrophotometry,,; ,،,؛o-aminophenol,,; ,،,؛m-aminophenol

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