Estimation of p-Aminophenol via Diazotization and Coupling Reaction with 4-Chlororesorcinol –Application on Paracetamol

Alhafhd, Hiba Abdul Salam; Othman, Nabeel S.

doi:10.33899/rjs.2022.172930

	Estimation of p-Aminophenol via Diazotization and Coupling Reaction with 4-Chlororesorcinol –Application on Paracetamol
Rafidain Journal of Science
Article 4, Volume 31, Issue 1, 2022, Pages 35-46 PDF (732.29 K)
Document Type: Research Paper
DOI: 10.33899/rjs.2022.172930
Authors
Hiba abdul salam Alhafhd^* ¹; Nabeel S. Othman²
¹Chemistry Department ./ College of Education for Pure Science/ University of Mosul , Mosul, Iraq
²Department of Chemistry/ College of Science/ Mosul University
Abstract
A spectrophotometric method has been proposed for the direct determination of p-aminophenol (p-Amp). The method includes diazotisation of p-Amp using an excess of sodium nitrite and in the presence of hydrochloric acid, and after destroying the remaining nitrous acid by adding sulphamic acid, then the produced diazonium salt coupled with the reagent 4-chlororenocinol (4-Chlr) in an alkaline medium of sodium hydroxide to form a water-soluble azo dye that gives the highest absorption at the wavelength of 488 nm. The linear range that follows Beer's law was from 0.5 to 15 μg/ml. The value of the molar absorptivity was 1.9905x10⁴ l/mol. cm. After investigation of the optimal conditions by studying all factors affecting the absorption of the formed azo dye. The method was applied to estimate paracetamol in its pharmaceutical preparations after hydrolysis process. The results of standard addition method proved that there is no interference by additives.
Keywords
p-aminophenol; the diazotisation and coupling reaction; 4-chlororesorcenol; paracetamol

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