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Biochemistry Research International
Volume 2015, Article ID 381721, 6 pages
Research Article

Comparative Analysis of the Properties of Acid-Base Indicator of Rose (Rosa setigera), Allamanda (Allamanda cathartica), and Hibiscus (Hibiscus rosa-sinensis) Flowers

1Directorate of Research and Development, Nigerian Institute of Leather and Science Technology (NILEST), Zaria 810001, Kaduna State, Nigeria
2Directorate of Science Laboratory Technology, NILEST, Zaria 810001, Kaduna State, Nigeria
3Department of Medical Laboratory Services, Antiretroviral Therapy Centre, Central Hospital, Agbor 321251, Delta State, Nigeria

Received 23 September 2015; Revised 5 November 2015; Accepted 9 November 2015

Academic Editor: Robert J. Linhardt

Copyright © 2015 Stanley I. R. Okoduwa et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The need to develop effective alternative for synthetic indicators is the demand of present-day chemistry. The acid-base indicator properties of Rose (Rosa setigera), Allamanda (Allamanda cathartica), and Hibiscus (Hibiscus rosa-sinensis) flowers were examined. Colour pigments were extracted from the flowers via cold and solvent extraction using soxhlet extractor. The pH value of the extracts with wavelengths of absorption was determined using ultraviolet spectrophotometer. From the results obtained, all the extracts exhibited sharp contrast between their colours in acid and base. Their pH was found to be 5.5 for cold extract of Rose and 5.6 for solvent extraction, 5.24 for cold extract of a Hibiscus and 6.52 for solvent extraction, 5.35 for cold extract of Allamanda, and 5.45 for solvent extraction. The maximum wavelengths of absorption obtained for all the extract fall within the visible region of electromagnetic spectrum. These values are almost similar to that obtained from synthetic indicators. It is on these bases that we concluded that natural indicators could be an excellent replacement for synthetic indicators since they are cheap, readily available, simple to extract, not toxic, user and environmentally friendly.