African Journal of
Pure and Applied Chemistry

  • Abbreviation: Afr. J. Pure Appl. Chem.
  • Language: English
  • ISSN: 1996-0840
  • DOI: 10.5897/AJPAC
  • Start Year: 2007
  • Published Articles: 357

Full Length Research Paper

Preliminary characterization of some natural dyes

Mercy Amarachukwu Ezeokonkwo
  • Mercy Amarachukwu Ezeokonkwo
  • Department of Pure and Industrial Chemistry, University of Nigeria, Nsukka, 410001, Enugu State, Nigeria.
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Sunday Nwankwo Okafor
  • Sunday Nwankwo Okafor
  • Department of Pharmaceutical and Medicinal Chemistry, University of Nigeria, Nsukka, 410001, Enugu State, Nigeria.
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Evelyn Uloma Godwin-Nwakwasi
  • Evelyn Uloma Godwin-Nwakwasi
  • Department of Chemistry, Gregory University, Uturu, Abia State, Nigeria.
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  •  Received: 27 July 2018
  •  Accepted: 12 September 2018
  •  Published: 30 September 2018

Abstract

A preliminary study on the chemical structure of dyes from Rothmannia hispidia, Pterocarpus osun and Terminalia superba was made using chemical tests, UV-visible and infrared spectroscopies. R. hispidia dye was found to contain an alkyl amino group (-NHR) and carbon-carbon double bond conjugated with a carbonyl (C = O) group, and also showed maximum absorption at 595 nm in the visible region. P. osun dye contains conjugated systems, hydroxyl (-OH) and amino (NHR) groups and showed maximum absorption at 506 nm in the visible region whereas T. superba dye is made up of conjugated system, nitro (NO2) and hydroxyl (-OH) groups. It showed maximum absorption at 478 nm in the visible region.

Key words: Rothmannia hispidia, Pterocarpus osun, Terminalia superba, dyes, characterization.