STUDY OF CELOSIA CRISTATA AS NATURAL INDICATOR FOR ACID-BASE TITRATIONS

1. Associate Professor, Department of Pharmaceutical Chemistry, Vaageswari College Of Pharmacy, Karimnagar, Telangana, India. 2. B. Pharm, Vaageswari College of Pharmacy, Karimnagar, Telangana, India. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 05 June 2020 Final Accepted: 10 July 2020 Published: August 2020


ISSN: 2320-5407
Int. J. Adv. Res. 8(08), 216-218 217 An indicator is a substance that changes color in solution over a narrow range of p H values. Some indicators change from one color to another, while the others change between colored and colorless states. P H indicators are usually weak acids or weak bases which are commonly employed to mark the end point of an acid-base titration [4]. Titrimetric analysis remains an important analytical technique in pharmaceutical analysis. It enables keen monitoring of the acid and base contents of raw materials, reaction mixtures, and resulting finished products in the industrial setting [5].
In acid-base titrations, acids are titrated with bases and bases are titrated with acids. They are also called as neutralization reactions, with the end point conformed either by use of colour indicators or potentiometrically with a glass electrode [6,7].
The German chemist Richard Willstatter demonstrated that plant pigmentation is due to the presence of anthocyanins which are glycosides. They exist in all tissues of higher plants including leaves, stems, roots, flowers and fruits which impart different colors. This gives an opportunity to use plants as natural acid-base indicators [8].
The substances that change colour when the acidity of the solution changes are known as acid-base indicators [9].
Acidimetry and alkalimetry deals with the titration of free bases with standard acid and also titration of free acids with a standard base independently. The reactions involve the combination of hydrogen and hydroxyl ions to form water [10].
Halocline chemical compound which is a p H indicator is added in little amounts to a solution so p H of the solution can be recovered [11].
In present study, we used Celosia cristata ethanolic extract as natural acid-base indicators in acid-base titrations. This plant is used as ornamental plant in garden and a parasiticide and poultice. These are used in the treatment of bloody stools,hemorrhoid bleeding,uterinebleeding,leucorrhoea, dysentery and diarrhoea.
The fresh flowers were collected from local areas and were authenticated by BOTANICAL SURVEYOF INDIA,HYDERABAD and AuthenticationNo:BSI/DRC/2019-2020/Identification/743.The flowers were cleaned and cut into small pieces and are shade dried.100grams of these pieces were macerated with 150ml of solution containing 9parts of ethanol and 1 part of dilute hydrochloric acid for 24hrs.The extract is filtered using muslin cloth and filter paper and stored in tightly closed container and away from sunlight. 10 ml of titrant and 3drops of indicator was titrated. All the parameters for the experiment are given in table-1. Each titration was carried for 3 times and the results was recorded. The ethanolic extract of the flower of Celosia cristata was screened for its use as an indicator for acid base titrations and the results were compared with the results of standard indicators

Results and Discussion:-
The extract of Celosia cristata flower was tested for its use as an indicator in acid-base titration and the results was compared by using standard indicators like phenolphthalein and methyl Orange.The results of strong acid-strong base (HCL Vs NaOH), weak acid-strong base (CH 3 COOH Vs NaOH), strong acid-weak base (HCL Vs NaHCO 3 ), weak acid-weak base (CH 3 COOH Vs NAHCO 3 ) titrations are listed in the below table-1.

Conclusion:-
The overall results obtained from all types of acid base titrations in the present study shows that the celosia cristata flower extract could be productively used as an acid base indicator due to the presence of anthocyanins and owing to the factors like wild availabilityof the flower, easy preparation and accurate and precise results and therefore it is used as an alternative to standard indicators.