A.O. Adetuyi  , 
    A Baseline Assessment Study of the Pigmentary Colours from Common Horticulture Plants Using UV-Visible Spectroscopy,
    Journal of Engineering and Applied Sciences,
    Volume 2,Issue 4,
    2007,
    Pages 750-752,
    ISSN 1816-949x,
    jeasci.2007.750.752,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2007.750.752)
    Abstract: Pigmentary colours from ten ornamental horticulture flowering plants commonly found in Akure metropolis, Ondo State, Nigeria, were steeped extracted in various solvents and analyzed using UV-visible spectroscopy.  All  the  pigments  extracted  exhibited  strong  absorptions  in the visible region of the range 400-580 nm. Bougainvillea and Allamanda flowers manifested various hues in acidic and basic media, showing that they could be used as indicators in a titration where a change in pH equivalent of the environment is required such as acid-alkali titration.
    Keywords: Pigmentary colours;horticulture;flowers;indicator;UV-visible spectroscopy