Use of Butterfly Pea (Clitoria ternatea) Extract as an Indicator in Acid Base Titration

Butterfly pea flowers are native plants from Southeast Asia that have two colors, purple and blue. This striking color is known to contain anthocyanin and chlorophyll. Anthocyanin compounds give different color responses to different pH conditions, so with these properties butterfly pea flower extract can potentially be a bioindicator of acid-base titration. The anthocyanin content of butterfly pea flower extract depends on the solvent used in the extraction process. In this experiment, dried butterfly pea flowers were extracted with 70% ethanol and 25% acetic acid with a ratio of 7: 1. The experimental results showed that the type of anthocyanin contained in dried butterfly pea flower extract in ethanol and acetic acid solvents was cyanidin. The pH range of the dried butterfly pea flower indicator for acidimetry at pH 3-5 by showing purple color, while for alkalimetry at pH 8-9 with yellowish green color. A pH below 3 indicates red while pH above 9 will show yellow and PH 6-7 shows a turquoise color. Indicator solutions still provide good results after a four-week storage period. This shows that the application of butterfly pea flower extract bioindicator is quite good in alkalimetry titration.