How do you make a standard curve for ascorbic acid?
Standard Curve Preparation: a. Dilute the standard to 1 mM by adding 10 μl of the 100 mM Ascorbic Acid Standard to 990 μl of distilled water, mix well. Add 0, 2, 4, 6, 8, 10 μl into each well individually.
What is a standard absorbance calibration curve?
Standard curves are graphs of light absorbance versus solution concentration which can be used to figure out the solute concentration in unknown samples.
Why is a 0.1 ascorbic acid solution used as the standard?
Ascorbic acid is used as standard because of its availability in different food sources (especially citrus fruit extracts). Ascorbic acid gives better result than gallic acid,mainly gallic acid is used for determination of phenolic content as standard.
How do you make a standard calibration curve?
To construct the calibration curve, use a computer program to plot the data as signal vs. concentration. Use the standard deviation of the repeated measurements for each data point to make error bars. Remove portions of the curve that are non-linear, then perform a linear regression and determine the best-fit line.
What is standard ascorbic acid?
Ascorbic acid or Vitamin C is the strongest natural water-soluble antioxidant, commonly used to measure antioxidant capacity. It is present in biological samples, like plasma, and food samples as a natural component of fruit and vegetables or as an additive.
What is IC50 of ascorbic acid?
The IC50 value of ascorbic acid was less than 10 approx to be 6.1 μg/mL. IC50 value was observed 28 μg/mL for the MeOH extract and 36 for BuOH extract. From Figure 1 and Table 1, it is observed that both extracts show significant DPPH radical scavenging property.
What is the purpose of calibration curve?
Calibration curve is a regression model used to predict the unknown concentrations of analytes of interest based on the response of the instrument to the known standards.
How do you describe a calibration curve?
In analytical chemistry, a calibration curve is a general method for determining the concentration of a substance in an unknown sample by comparing the unknown to a set of standard samples of known concentration. The concentrations of the standards must lie within the working range of the technique they are using.
Why ascorbic acid is used as standard in Dcpip?
Ascorbic acid reacts with DCPIP, changing the colour from blue to colourless. They react in a 1:1 fashion, so if a known quantity of DCPIP solution reacts with the plant tissue extract, the quantity of DCPIP used gives a direct measure of the quantity of ascorbic acid present.
Why is ascorbic acid a strong reducing agent?
It is a mild reducing agent and antioxidant. It is oxidized with loss of one electron to form a radical cation and then with loss of a second electron to form dehydroascorbic acid. Sometimes these radicals initiate chain reactions. Ascorbate can terminate these chain radical reactions by electron transfer.
What is the principle of ascorbic acid?
PRINCIPLE : Redox reaction of ascorbate with 2,6- dichlorophenol indophenol in acid solution involves reduction of this dye to a colourless leucobase while ascorbate is oxidized to dehydroascorbate. In blood and urine the vitamin is mainly present as ascorbate in fresh samples.
How to make an ascorbic acid calibration curve for?
It is not Ascorbic vs DPPH but by doing ascorbic acid scavenging activity on DPPH by different concs. You can generate the equation. but if want to use AA as positive control, you may need use other known compound for standard instead.
How can I make the standard curve for Galic acid?
1. Preparation of Galic Acid solutions: 5 solutions were prepared with the following concentrations: 3g/l; 2.1 g/L; 1.5g/L; 0.9g/L and 0.3g/L 2. Preparation of my sample: 0.25g of sample was mixed with 5 ml of methanol
How to determine the amount of ascorbic acid in fruit juice?
To determine the amount of ascorbic acid in fruit juice at room temperature, refrigerated, and heated. A spectrophotometer will be used to create a standard curve to use to determine the amount of ascorbic acid in our samples. (Top) The molecular structure of Ascorbic acid, a reducing agent is shown.
How to make ascorbic acid with para film?
The stock solution of ascorbic acid is 200 ug/ml. Use M1V1=M2V2 to make 2mL of each ascorbic acid concentration. Once solutions are made, cover them with para-film. Add 3 ml of sodium citrate buffer to each of the tubes. Each team will run a control (room temperature) and two other treatments (heated and refrigerated) of juice.