Define Sample Titration - estimation of vitamin c in chillies?
Take a clean and dry large chilli and weigh it. Note the weight of the chilli. Grind the chilli to a fine paste in a pestle and mortar adding some sand to it for finer grinding. Add a few drops of 6% metaphosphoric acid while grinding. Transfer the contents carefully to a 50ml volumetric flask ensuring that not a drop spills. Rinse the pestle and mortar with 3% metaphosphoric acid and transfer the rinsing to the volumetric flask. Repeat this twice until all the paste has been transferred to the volumetric flask. Make the volume to 50 ml mark with 3% metaphosphoric acid. Mix the contents and filter the solution through glass wool and then through a dry filter paper into a dry flask or beaker. Pipette 10 ml of this solution and titrate with 2,6 dichlorophenol indophenol solution till a light pink colour is seen that persists for 30 seconds. Calculate the ascorbic acid content in the chilli.