Spectrophotometric Determination of Benzocaine by Azo-Dye Formation Reaction with N - (1-naphthyl)ethylenediamine as Coupling Agent

• Main Authors: W. Bashir, N. Othman
• Format: Article
• Language: Arabic
• Published: College of Education for Pure Sciences 2005-06-01
• Series: مجلة التربية والعلم
• Subjects: benzocaine; ethylenediamine; coupling agent
• Online Access: https://edusj.mosuljournals.com/article_162863_7a97aa093578f23a09365ba441dd5181.pdf

A simple spectrophotometric method for the determination of benzocaine in aqueous solution is developed. The method based on the coupling of diazotized benzocaine with N-(1-naphthyl)ethylenediamine(N-NED) in acidic<br />rnedium. The purplish - violet azo dye formed is water soluble, stable, and shows tnaximum absorption at 547.5 nm. Beer's law is obeyed over the range 10 - 100 ptg I 25 ml, i.e, 0.4 - 4 ppm with a molar absorptivity of 5.56 x 104l.mol-r.cm-' and Sandell's sensitivity index of 0.0029 pg.cm-2, arelative error of - 0.660 to * 0.002% and a relative standard deviations of*0.110to+ 0.550% depending on the concentration. The method has been applied to<br />determine benzocaine in two synthetic pharmaceutical preparations.