2024/08/29 by Saeed, Adel
paper · doi:10.48317/imist.prsm/morjchem-v12i4.48619
This study explores the potential of extracting pigments from common plants as renewable alternatives to synthetic pH indicators. Betalain from beetroot (S1), anthocyanin from red cabbage (S2), and curcumin from turmeric (S3) analyzer of plant pigments by using devices UV-Vis spectroscopy in the wavelength 200-1100 nm. The electronic spectra exhibited maxima peak at 530(S1, S2), and 405 (S3), nm, respectively. IR spectroscopy both of the preceding plant dyes exhibit absorptions at frequencies commonly expressed in wavelength number 1/( characteristic of stretching and bending modes of the C=N, C=O, and other groups. some physical properties were studied of these dyes, obtained very good solubility in a water solvent, colorimetric response was tested by the addition of solution samples to strong-weak, acid-base, and color changes occurred at different pH ranges. Color stability assessment of liquid and solid samples was observed at different times: 5, 15, 60, and 360 minutes. Dyes were assessed for their ability to indicate the endpoint in acid-base titrations. The color of S1, S2, and S3 were compared to phenolphthalein and methyl orange in different acid-base solutions. The pH values at the color change endpoints were highest for S3 (5.45), followed by S1 (5.42) and S2 (5.19). Conductivity measurements showed S1 had the highest conductivity, followed by S3 and S2, indicating their electrolytic properties. Titrations of strong acid-base, weak acid-strong base, weak acid-weak base, and strong acid-weak base systems demonstrated that S1, S2, and S3 reliably indicate the equivalence point, comparable to commercial indicators. The extracts' chemical properties, low cost, and environmental friendliness support their potential as green alternatives for acid-base analysis.