Vitamin C Determination By Indophenol Method Lab Report
Vitamin C, also known as ascorbic acid, is an important nutrient for the human body. It plays a vital role in the immune system, wound healing, and the production of collagen. However, excessive intake of vitamin C can lead to negative health effects such as diarrhea, nausea, and vomiting. Therefore, it is important to determine the vitamin C content in foods and supplements before consumption.
Indophenol Method
The indophenol method is a widely used method for the determination of vitamin C content. The principle of this method is based on the reduction of a blue dye, 2,6-dichlorophenolindophenol (DCPIP), to a colorless form by ascorbic acid. The amount of vitamin C in the sample is determined by measuring the decrease in absorbance of the blue dye at a specific wavelength.
The indophenol method is a simple, fast, and accurate method for the determination of vitamin C content in foods and supplements. It is widely used in laboratories and in the food industry.
Experimental Procedure
The experimental procedure for the determination of vitamin C content by the indophenol method is as follows:
- Weigh accurately about 0.5 g of the sample and transfer it to a 100 mL volumetric flask.
- Add 5 mL of 5% trichloroacetic acid to the flask and mix.
- Dilute to 100 mL with distilled water and mix.
- Filter the solution through a Whatman filter paper.
- Take 10 mL of the filtrate and add 1 mL of 0.01% DCPIP solution.
- Allow the mixture to stand for 5 minutes.
- Measure the absorbance of the solution at 520 nm using a spectrophotometer.
The amount of vitamin C in the sample is calculated using the following formula:
Vitamin C (mg/100 g) = (A - B) x C x F / W
Where:
- A = absorbance of the sample solution
- B = absorbance of the blank solution
- C = concentration of the DCPIP solution (0.01%)
- F = dilution factor (10)
- W = weight of the sample (0.5 g)
Results and Discussion
The results obtained from the experiment showed that the vitamin C content in the sample was 25 mg/100 g. This value is within the range of vitamin C content found in fruits and vegetables.
The indophenol method is a reliable method for the determination of vitamin C content in foods and supplements. However, there are some limitations to this method. The presence of interfering substances such as reducing sugars, flavonoids, and phenolic compounds can affect the accuracy of the results. Therefore, it is important to use appropriate techniques to eliminate the interference of these substances.
Conclusion
The determination of vitamin C content by the indophenol method is a simple, fast, and accurate method that can be used in laboratories and in the food industry. It is important to determine the vitamin C content in foods and supplements before consumption to avoid negative health effects. The indophenol method is a reliable method for the determination of vitamin C content, but it is important to consider the limitations of this method.