Volume 15, Issue 7 · IJARST · ISSN 2319-1783 / 2320-1126

Development and Comparative Assessment of Four Plant-Derived Natural Indicators for Sustainable Acid–Base Titrations

Development and Comparative Assessment of Four Plant-Derived Natural Indicators for Sustainable Acid–Base Titrations is an open-access, peer-reviewed research paper by Tushar S. Umasare, Mayur R. Badhe, Rajendra G. Halor, published in Volume 15, Issue 7 of the International Journal of Advanced Research in Science and Technology (IJARST), a UGC-approved journal (Print ISSN 2319-1783, Online ISSN 2320-1126).

Author

Tushar S. Umasare, Mayur R. Badhe, Rajendra G. Halor

Abstract

The growing need for environmentally sustainable and economical methods of analysis has led to the search for natural indicators of plants as substitutes for artificial acid-base indicators. This project involves the exploration of four plant extracts, namely the Jamun (Syzygium cumini) fruit extract, Raspberry (Rubus idaeus) fruit extract, Gulmohar (Delonix regia) flower extract, and Bougainvillea (Bougainvillea glabra) flower extract for their use as natural acid-base indicators. The extracts were prepared through aqueous and ethanolic extraction techniques, and the pH was measured by means of a digital pH meter, pH paper, and red-blue litmus paper. The indicator activity of the extracts was assessed on the basis of color change in the pH range of 1.12-13.02 through standard acids and bases. In addition to that, the practicality of use of the extracts was tested by means of strong acid-strong base (HCl vs. NaOH), strong acid-weak base (HCl vs. Na₂CO₃), weak acid-strong base (CH₃COOH vs. NaOH), and weak acid-weak base (CH₃COOH vs. Na₂CO₃) titrations, and these extracts were compared to the usual synthetic indicators – phenolphthalein and methyl orange. All four extracts showed clear, repeatable and pH-sensitive color change reactions that made it possible to determine the endpoints of acid-base titrations efficiently. Of all the tested extracts, the one from Jamun fruit had the most similar behavior to the synthetic indicators, while Raspberry, Gulmohar, and Bougainvillea extracts gave satisfactory results as well. It can be stated that the natural extracts, especially Jamun fruit extract, have high prospects of being used as inexpensive, biodegradable and environmentally friendly alternatives to synthetic indicators.

Keywords: Natural indicators; Acid–base titration; Syzygium cumini; Rubus idaeus; Delonix regia; Bougainvillea glabra; Anthocyanins; Green chemistry.

DOI: https://doi.org/10.62226/ijarst20262743

References:

1. Harris, D. C. Quantitative Chemical Analysis. 10th Edition. W. H. Freeman, New York, 2020.
2.  Christian, G. D.; Dasgupta, P. K.; Schug, K. A. Analytical Chemistry. 8th Edition. John Wiley & Sons, 2021.
3.  Skoog, D. A.; Holler, F. J.; Crouch, S. R. Principles of Instrumental Analysis. 7th Edition. Cengage Learning, 2018.
4. Mendham, J.; Denney, R. C.; Barnes, J. D.; Thomas, M. J. K. Vogel's Textbook of Quantitative Chemical Analysis. 6th Edition. Pearson Education, 2000.
5.  Barbosa, J.; Bosch, E.; Carrera, R. A Comparative Study of Some Hydroxyanthraquinones as Acid–Base Indicators. Talanta. 1985;32(11):1077–1081.
6. Mebane, R. C.; Rybolt, T. R. Edible Acid–Base Indicators. Journal of Chemical Education. 1985;62(4):285.
7. Gałuszka, A.; Migaszewski, Z. M.; Namieśnik, J. The 12 Principles of Green Analytical Chemistry. Trends in Analytical Chemistry. 2013;50:78–84.
8.  Płotka-Wasylka, J. A New Tool for the Evaluation of Analytical Procedures: Green Analytical Procedure Index (GAPI). Talanta. 2018;181:204–209.
9. Kharat, M. et al. Efficacy of Plant Extracts as Green Indicators in Acid–Base Titrimetric Analysis: Perspective Towards Green Chemistry. Microchemical Journal. 2025;213:113613.
10.  Khoo, H. E.; Azlan, A.; Tang, S. T.; Lim, S. M. Anthocyanidins and Anthocyanins: Colored Pigments as Food, Pharmaceutical Ingredients, and the Potential Health Benefits. Food & Nutrition Research. 2017;61:1361779.
11.  He, J.; Giusti, M. M. Anthocyanins: Natural Colorants with Health-Promoting Properties. Annual Review of Food Science and Technology. 2010;1:163–187.
12.  Castañeda-Ovando, A. et al. Chemical Studies of Anthocyanins: A Review. Food Chemistry. 2009;113(4):859–871.
13.  Giusti, M. M.; Wrolstad, R. E. Characterization and Measurement of Anthocyanins by UV–Visible Spectroscopy. Current Protocols in Food Analytical Chemistry. Wiley, 2001.
14.  Kapilraj, N.; Keerthanan, S.; Sithambaresan, M. Natural Plant Extracts as Acid–Base Indicator and Determination of Their pKa Value. Journal of Chemistry. 2019;2019:2031342.
15.  Killedar, S. G. Screening and Implementation of Bougainvillea spectabilis Bract Extract as an Indicator in Acid–Base Titrations. International Journal of Green Pharmacy. 2015.
16.  Zulfajri, M.; Muttakin. Activity Analysis of Anthocyanin from Syzygium cumini (L.) Skeels as a Natural Indicator in Acid–Base Titration. Rasayan Journal of Chemistry. 2018;11(1):135–141.
17.  Brito, B. N. C. et al. Anthocyanins of Jambolão (Syzygium cumini): Extraction and pH-Dependent Color Changes. Journal of Food Science. 2017;82(10):2286–2290.
18.  Kaur, D. et al. Syzygium cumini Anthocyanins: Recent Advances in Biological Activities, Extraction, Stability, Characterisation and Utilisation in Food Systems. Food Production, Processing and Nutrition. 2024;6:34.
19.  Giampieri, F. et al. The Healthy Effects of Strawberry, Blueberry, Raspberry and Blackberry Polyphenols: A Review. Journal of Berry Research. 2015;5:1–31.
20.  Rahman, M. M. et al. Phytochemical Profile and Antioxidant Potential of Delonix regia Flower Extracts. Plants. 2023;12:1956.
21.  Ayyanar, M.; Subash-Babu, P. Syzygium cumini (L.) Skeels: A Review of Its Phytochemical Constituents and Traditional Uses. Asian Pacific Journal of Tropical Biomedicine. 2012;2(3):240–246.
22.  Andersen, Ø. M.; Jordheim, M. Anthocyanins. In: Flavonoids: Chemistry, Biochemistry and Applications. CRC Press, 2010.
23. IUPAC. Compendium of Chemical Terminology (Gold Book). International Union of Pure and Applied Chemistry. 2019.
24. United States Pharmacopeia (USP). General Chapter 541: Titrimetry. USP 2023.
25. G. Pandit, K. Satasiya, P. Khanpara and  S. Faldu, Herbs as a natural pH indicators,  Journal of Pharmacognosy and Phytochemistry, 2023; 12(6): 01-04.
26. Chikkam Anusha, Shaik N. ,Vemula B., K. G. Reddy, Nuthalapati A. K., Manelli S., Preparation And Evalution of Natural Acid Base Indicators From Different Flowers, Indo Am. J. P. Sci, 2025; 12 (03), 146-151.
27. D. A. Gwarzo, J. S. Suleiman, I. M. Idriss, Extraction And Application of Some Natural Flower Pigments As Acid-Base Indicators,  FUDMA Journal of Sciences, 2023, 7 (4), 157-162.

DOI

https://doi.org/10.62226/ijarst20262743

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How do you cite this paper?

Tushar S. Umasare, Mayur R. Badhe, Rajendra G. Halor — “Development and Comparative Assessment of Four Plant-Derived Natural Indicators for Sustainable Acid–Base Titrations.” International Journal of Advanced Research in Science and Technology (IJARST), Volume 15, Issue 7. DOI: https://doi.org/10.62226/ijarst20262743.

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