NATURAL INDICATORS

Natural indicators a comparative study of the synthetic indicator

1. NATURAL ACID-BASE INDICATORS BY USING DIFFERENT PLANT EXTRACTS

2. ANDHRA UNIVERSITY SEMINAR -2022 M.TECH BIOTECHNOLOGY CONTENTS AIMS AND OBJECTIVES INTRODUCTION MATERIALS &METHODS RESULTS &DISCUSSION SUMMARY&CONCLUSION SUBMITTED TO BEENA MAM PROFESSOR Advanced MicroBiology

3. AIMS & OBJECTIVES

4. Aims and Objectives: AIM : To Carry out Acid-base Titration by using different plant extracts as natural indicators. Objectives: To substitute synthetic indicators with natural indicators in performing acid -base titrations. To evaluate the indicator property of natural pigments. Using different plant extract as indicator is more economical and with the same accuracy of result as that given by syntheticindicator . To analyse unknown samples. To identify eco friendly , non-toxic natural indicators.

5. INTRODUCTION :

6. Titration : Titration is a common laboratory method of quantitative chemical analysis to determine the concentration of an identified analyte. A reagent, termed the titrant or titrator, is prepared as a standard solution of known concentration and volume. At the equivalence point of a titration, an exactly equivalent amount of titrant has been added to the sample. The experimental point at which the completion of the reaction is marked by some change is called the end point. Titrations, classified according to the nature of the chemical reaction occurring between the sample and titrant, include: Acid-base titrations, Precipitation titrations Complex-formation titrations, Oxidation-Reduction (Redox) titrations. The basic principle of the titration is the following: A solution - also called titrant or standard solution - is added to sample to be analyzed. The titrant contains a known concentration of a chemical which reacts with the substance to be determined In acid-base titration (i.e., the titration of an acid with a base, or vice versa), the indicator is a substance that can exist in two forms, an acid form and a basic form, which differ in colour . A wide choice of acid-base indicators is available, varying not only in the colours of the two forms but also in their sensitivity toward acid or base. Types of titration are on based on acid- base titration are : 1] strong acid-strong base [ sulphuric acid – potassium hydroxide] 2] strong acid-weak base [ sulphuric acid- water] 3] weak-acid-weak base [Acetic acid – water] 4] strong base-weak acid [potassium hydroxide –Acetic acid]

7. THE EXTRACTS OF THE FOLLOWING PLANTS ARE USED AS NATURAL INDICATORS : Beetroot vulgaris Tagetus erecta linn Hibiscus rosa sinensus Brassica oleraecea Gloriosa superba BEETROOT VULGARIS : The Beetroots (Beta vulgaris ) were procured from Vegetable Market. The peel of beetroot were discarded and the freshly cut pieces were used for sample preparations. Study Design: Preparation of Natural Indicator. HIBISCUS ROSA-SINESIS : Hibiscus rosasinensis was identified from the flora of Botany Department. Hibiscus rosasinensis was collected for the purpose of study of natural indicator. It is available throughout the year. Fresh petals were collected in the month of January and February because it is the blooming season of these plants. Natural indicator was isolated from the Hibiscus rosasinensis . Several plants pigment like Anthocyanin , Flavonoids occurs in petals of these flowers which acts like natural indicator. BRASSICA OLARECEA : The Red Cabbage were procured from Vegetable Market. The extract from boiled red cabbage is used as an acid-base indicator. TAGETES ERECTA LINN : Fresh flowers of Tagetes erecta were collected from the located area and the extract was obtained from the flowers of tagetes erecta . GLORIOSA SUPERBA : The flowers were collected through online .

8. Materials & Methods Materials : Materials used are chemicals like sulphuric acid , formic acid, potassium hydroxide ,Ethanol and distilled water & the different plant extracts of Beetroot vulgaris , Brassica oleracea , Hibiscus rosasinensus , tagetes erectalinn , & Gloriosa superba . 0.5 & 1 N Of different Acid-bases solution were prepared : Strong acid –strong base (H2SO4–KOH) Strong acid – weak base (H2SO4 –H2O) Weak acid - strong base (CH3COOH-KOH) Weak acid –weak base (CH3COOH - H2O) NORMALITY : Normality is define as the number of equivalents per liter of solution. N = grams solute / Volume solvent in liters * eq.wt N1V1 =N2 V2 Preparation Of Concentration Of Standard Solutions 0.5 N & 1 N are: Concentrated Sulphuric acid : To prepare 1000ml of 1N sulphuricacid from conc sulphuric acid 27.2 ml of conc acid is diluted upto 1000 ml of water. To prepare 0.5N of sulphuric acid will be use of half of its sulphuric acid conc (13.58) and make up to 1000ml of water. Potassium Hydroxide: Take 56.11g of KOH for 1N, Dissolve it in around 300 ml water. Transfer to a 1L measuring flask quantitatively ,dilute to 1 litre . To prepare 0.5N of KOH will be use of half of its KOH (28.05) and make up to 1000ml of water. Potassium Hydroxide: Take 56.11g of KOH for 1N, Dissolve it in around 300 ml water. Transfer to a 1L measuring flask quantitatively ,dilute to 1 litre . To prepare 0.5N of KOH will be use of half of its KOH (28.05) and make up to 1000ml of water. FORMIC ACID : To prepare 1000ml of 1N formic acid from57.47 ml of is diluted upto 1000 ml of water. To prepare 0.5N of formic acid will be use of half of its formic- acid (28.73) and make up to 1000ml of water

9. METHODOLOGY : BEETROOT VULGARIS : Flow chart:

10. Hibiscus rosa sinensus :

11. Tagetus Erecta linn :

12. Brassica olerecea :

13. RESULTS & DISCUSSION

14. Results and discussion : The following different plant extracts as Natural Acid Base indicators are obtained resultant and discussion as shown below : ACID-BASE TITRATION WITH DIFFERENT PLANT EXTRACTS AS INDICATORS : Synthetic & Natural indicators Acid –Base Titration with different plant extracts as indicators by using 0.5&1 Normality 0.5 N 1N SA&SB SA & WB WA & SB WA & WB SA & SB SA & WB WA & SB WA & WB phenophthalene 11 12.3 12 8.9 9.3 11.5 10 11.0 Methyl orange 23 1.6 28.4 4.6 13.0 1.4 18.2 2.9 Beet Root vulgaris 29 2.3 26.2 46.2 16.5 1.8 14.6 27.2 Tagetus erecta linn 15 15.3 13.2 38.4 9.8 9.6 10.0 22.0 Hibiscus rosasinesus 20 2.7 14.2 1.2 12.0 1.9 11.0 0.6 Brassica olarecea 11 12.3 12.7 9.8 9.3 11.5 9.8 11.2 Gloriosa superba 8.9 26.4 5.80 26.32 7.18 27.9 5.34 24.0

15. COLOUR CHANGE OF DIFFERENT PLANT EXTRACTS (INDICATOR) IN ACID –BASE TITRATION (START POINT TO END POINT) : Synthetic indicators Phenophthalene methyl orange SA & SB SA&WB WA & SB WA&WB SA & SB SA&WB WA & SB WA&WB

16. NATURAL INDICATORS Beet root vulgaris Tagetus erecta Hibiscus rosasinensus Brassicaoleraecea Gloriosasuperba SA &SB SA&SB SA&SB SA&SB SA&SB SA &WB SA &WB SA &WB SA &WB SA &WB WA &SB WA &SB WA &SB WA &SB WA &SB WA & WB WA & WB WA & WB WA & WB WA & WB

17. Titration results obtained using different plant extracts are shown in four sets of acid –bases like strong acid / strong base,( sulphuric acid –sodium hydroxide) strong acid / weak base,( sulphuric acid –water /Ammonium hydroxide), weak acid / strong base,( Acetic acid – sodium hydroxide) weak acid / weak base (Acetic acid –water / Ammonium hydroxide). It was carried out using two different normality of acids & alkalis viz .0.5 & 1N. All types titration shows equivalence point obtained by different plant extracts which are very closely to synthetic indicators. The results obtained showed that the routinely used indicator can be replaced successfully by different plant extracts. since, the PH of indicator of different plant of aqueous & Ethanolic extracts shows almost neutral . All natural components are ecofriendly moreover , colour changes which is observed on addition of plant extracts of aqueous & ethanolic showed that the colour was maintained for a long time . Thus, these indicators are stable. However aqueous extract of plant will be stored at four degree centigrade to avoid microbial contamination .where as ethanolic extracts can be stored at room temperature.

18. SUMMARY & CONCLUSION

19. SUMMARY & CONCLUSION:

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