ABSTRACT

This work highlights the use of acidified ethanolic extract of the queen Sirikit flower and Tumeric root as an acid - base indicator in acid base titration. The plants were extracted using 1000 ml of ethanol each. Promising results was obtained when it was tested against standard synthetic indicators. Titration shows sharp colour change at the equivalent point 20.00 to 24.00, and The flower extract showed visible color change at pH from 5 to 8. It was observed that for strong acid vs strong base titration, their titre values are 21.20, 17.30, 15.30and 15.40 for methyl orange, phenolphthalein, Tumeric extract and queen Sirikit respectively. For titration involving strong acid and weak base, the titre values of methyl orange, phenolphthalein, Tumeric extract and queen Sirikit extract are 38.80, 19.00, 19.00 and 19.50 respectively. For titration involving weak acid vs strong base, the titre values of phenolphthalein, Tumeric extract and queen Sirikit extract are 25.00, 24.20 and 25.00 respectively. And for weak acid vs weak base titration, the titre values of phenolphthalein, Tumeric extract and queen Sirikit extract are 21.50, 21.50 and 22.50 respectively. The phytochemical analysis showed the presence of tannins, alkaloids, Flavonoid, Saponin, sterol, phenol, and hydrogen cyanide in the plants. The results obtained from Tumeric sample, shows that HCN content was the highest at a value 2.88 ± 0.0 I mg/kg, followed by tannin at 1.075 ± 0.0075mg/l 00g, followed by alkaloid 0. 74 ± 0.005mg/1 OOg, and Saponin next with 0.55 ± 0.005mg/100g, while the value of Flavonoid 0.48 ± 0.01mg/l00g, phenol 0.27±0.005mg/100g, sterol having the least value of 0.125 ± 0.0025mg/100g. And from flower sample, it was observed that HCN content was the highest at a value 3.67 ± 0.015, followed by tannin at 1.045 ± 0.0025, followed by Saponin 0.485 ± 0.0025, and alkaloid next with 0.47 ± 0.005, while the value of phenol 0.31 ± 0.005m, Flavonoid 0.29 ± 0.005 and sterol having the least value of 0.0895 ± 0.00125. The phytochemical analysis shows that the Tumeric and Queen Sirikit flower has antioxidant and medicinal properties and can be used in the production of drugs for human health. This indicator was found to be useful in all type of acid - base titration. It was found to be very useful, economical, simple and accurate indicator for titrations.