Investigating the indicator properties of extracts from jacaranda Mimosifolia flowers and Amaranthus Blitum leaves to act as substitutes/alternatives to synthetic indicators

Abstract

Commonly used indicators for acid base titrations are synthetically produced from artificial substances. This study investigated use of natural and ecofriendly extracts from Jacaranda mimosifolia flower and Amaranthus Blitum leaves which were found to perform well in titrations with only a small difference (both positive and negative) of less than 1ml when compared with the titre values of synthetic indicators in the performed experiments. Clear sharp color changes from light green to pink were obtained during these titrations for both extracts, however Amaranthus Blitum leaf extracts produced distinctively better end points as compared to Jacaranda mimosifolia and therefore Amaranthus Blitum was more recommended for use and more attention was given to Amaranthus Blitum during the study. Furthermore, it was established that phytochemicals known as Leucoanthocyanins were responsible for the color changes in Jacaranda Mimosifolia extract whereas phytochemicals known as flavones were responsible for color changes in Amaranthus Blitum extract. The pKa value of Amaranthus Blitum was determined as 7.5399. Since production of these natural indicators is very simple, cost effective, has an environment friendly extraction procedure and excellent performance with sharp end point color changes it is possible to use these extracts as potential substitutes for synthetic indicators in acid base titrations.