SPECTROPHOTOMETRIC ANALYSIS OF COLOURANT EXTRACTS FROM THREE Different COLOURED Flowers of Tagetus erecta (L) AT DIFFERENT pH VALUES
Spectrophotometric analysis of the natural colourants from three different coloured flowers of Tagetus erecta (L) were carried out at different pH values. The results show that Tagetus erecta (L) extract (colourant) was stable at the experimental pH range of 2.60 – 9.36 (Light yellow coloured flowers) and 4.0- 12.0 (Orange coloured flowers) and 2.48 – 8.40 (Brown coloured flowers). This was indicated by the similar peaks of absorption maxima at the different pH values. Beer’s law is valid over the concentration range of 50 - 400 ppm. The colourant extract has absorption maximum at 470 nm, 410 nm and 480 nm respectively. Tagetus erecta (L) extract, with further studies could be used as a colourant in pharmaceutical formulations.
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