What happens when DCPIP is added to vitamin C?
DCPIP is a dye. It is blue color when in oxidizing form and colorless in reduction form. When DCPIP is added into vitamin C solution, the vitamin C reduces the dye, then, decolorizes the dye. Therefore, the decolorization of DCPIP indicates the presence of vitamin C.
Which method is used to determine the concentration of ascorbic acid concentration?
Fluorometric Method. Fluorometric analysis has been used for ascorbic acid assay in pharmaceutical preparations, beverages, special dietary foods and even for human serum (Arya, Mahajan and Jain, 2000).
What colour is DCPIP at pH 7?
DCPIP is blue when oxidised (at pH 7.0) and colourless when reduced, so it is possible to monitor the loss of blue colour as an indication that DCPIP has accepted electrons.
What is DCPIP titration?
This experiment uses 2,6-dichlorophenolindophenol (DCPIP) in a titration, to estimate the concentration of vitamin C in food. DCPIP is blue when dissolved in water and is red in acid conditions, and is reduced by ascorbic acid (vitamin C) to a colourless compound.
What is the principle of vitamin C titration?
As long as vitamin C is present in the solution, the triiodide is converted to the iodide ion very quickly. However, when all the vitamin C is oxidized, iodine and triiodide will be present, which react with starch to form a blue-black complex. The blue-black color is the endpoint of the titration.
How do you titrate vitamin C?
Titrating Juice Samples
- Add 25.00 ml of juice sample to a 125 ml Erlenmeyer flask.
- Titrate until the endpoint is reached. (Add iodine solution until you get a color that persists longer than 20 seconds.)
- Repeat the titration until you have at least three measurements that agree to within 0.1 ml.
What method is used to test for vitamin C content?
There are several methods to determine the ascorbic acid concentration in food products, such as spectrometry , titrimetry , or high-performance liquid chromatography (HPLC) [11,12].
Why does vitamin C turn DCPIP Colourless?
Using DCPIP to determine the concentration of ascorbic acid or Vitamin C in a solution. DCPIP is commonly used as an indicator for Vitamin C. If vitamin C, which is a good reducing agent is present , the blue dye, which turns pink in acid conditions and is reduced to a colourless compound by ascorbic acid.
Why is HCl added for the titration of vitamin C?
Answer and Explanation: Hydrochloric acid (HCl) is added during titration of vitamin C (C6H8O6) because the reaction should be carried out in an acidic medium.
Which indicator is used for the titration of ascorbic acid?
Ascorbic acid can be titrated with a base (sodium hydroxide, NaOH) using the indicator, phenolphthalein.
Why do we need to add sodium bicarbonate during the analysis of vitamin C?
Vitamin C and sodium bicarbonate enhance the antioxidant ability of H9C2 cells and induce HSPs to relieve heat stress – PMC. The .
Why do we use HCl in iodometric titration?
Firstly, iodometric titration is a redox process, so acids which can oxidize or be oxidized should not be used. Nitric acid is an oxidizer, hydrochloric acid can be oxidized to chlorine, so these should not be used. Both sulfuric acid and acetic acid are free of these problems.
What colour does Dcpip go in vitamin C?
The principle of this method is a titration with dichlorophenolindophenol (or phenol-indo-2:6-dichlorophenol, also known as DCPIP). Ascorbic acid reacts with DCPIP, changing the colour from blue to colourless.
Why does DCPIP change Colour when reduced?
DCPIP. DCPIP is a redox dye commonly used as a monitor of the light reactions in photosynthesis because it is an electron acceptor that is blue when oxidized and colourless when reduced. DPIP is commonly used as a substitute for NADP+. The dye changes color when it is reduced, due to its chemical structure.
Does sodium bicarbonate neutralize vitamin C?
Additionally, as a weak base, sodium bicarbonate can neutralise the strong acidity of vitamin C without destroying its electron donor and antioxidant activities (Padayatty and Levine 2016).
How do you add DCPIP to vitamin C solution?
d Using a graduated pipette or a burette, add 1% DCPIP drop by drop to the vitamin C solution. Shake the tube gently after adding each drop. Add DCPIP solution until the blue colour of the final drop does not disappear. e Record the exact amount of DCPIP solution that was added. f Repeat the procedure and calculate an average result.
How can I quantitatively measure Vitamin C using DCIP?
Before using DCIP to quantitatively measure vitamin C, you must know the concentration of the DCIP solution. You can use the reaction of the DCIP solution with a solution of ascorbic acid with a known concentration to find the concentration of the DCIP solution.
How to determine the concentration of vitamin C in solution?
Determination of the concentration of vitamin C by using DCPIP test. Squeezing pipette/ dropper. pipette & pipette filler. Test-tube & test-tube rack. Apparatus required:. DCPIP solution.
How do you make a DCPIP test?
a Make up a 1% solution of vitamin C with 1 g of vitamin C in 100 cm 3; this is 10 mg cm –3. b Make up a 1% solution of DCPIP. c Pipette 2 cm 3 of vitamin C solution into a test tube. d Using a graduated pipette or a burette, add 1% DCPIP drop by drop to the vitamin C solution. Shake the tube gently after adding each drop.