577 Mg Of Vitamin Unknown 44 2 example essay topic

Vitamin C Content of Apple Juice Introduction Complete lack of ascorbic acid (a. k. a Vitamin C) in the diets of humans and other primates leads to a classic nutritional disease, scurvy. This disease was widespread in Europe during the fifteenth and sixteenth centuries, but it is rare today. Ascorbic acid is widely distributed in nature, but it occurs in extremely high concentrations in citrus and green plants such as green peppers and spinach. Ascorbic acid can be synthesized by all plants and animals, with the exception of humans, other primates, and guinea pigs. Therefore, vitamin C must be present in our dietary substances.

The fundamental role of ascorbic acid in metabolic processes is not very well understood. There is some evidence that it may be involved in metabolic reactions of tyrosine, proline, and some steroid hormones, and in the cleavage-oxidation of acid. Its function in these metabolic processes appears to be related to the ability of vitamin C to act as a reducing agent. The adult Recommended Daily Allowance f vitamin C is 70 mg per day. Some scientists and physicians have suggested doses up to 1 to 3 grams per day in order to help resist the common cold. Deficiency of vitamin C results in swollen joint, abnormal development and maintenance of tissue structures, and eventually scurvy.

Determination of vitamin C in biological fluids such as boll d and urine is difficult because only small amounts of the vitamin are present and many interfering reducing agents are present. Substances containing groups, sulfite, and are common in biological fluids and react with DCIP, but much more slowly than ascorbic acid. The interference by is often minimized by the addition of p- acid. Materials and Supplies Apple JuiceMetaphosphoric acid / Acetic acid solution 4%Unknown ascorbic acid in meta phosphoric acid / acetic acid solution, . 5 mg / ml 2, 6 solution in water Ascorbic acid oxidase, lyophilized water Experimental Procedure Standard Ascorbic Acid Solution Fill a micro buret with DCIP solution. Using a pipe t, transfer 1.0 ml of the ascorbic acid standard solution to a 50 ml Erlenmeyer flask containing 5 ml of 4% meta phosphoric acid solution.

Read and record the initial reading on the buret. Titrate by rapid, drop wise addition of DCIP from the buret while mixing the contents of the flask. Add DCIP solution until a distinct rose-pink color persists for 15-20 seconds. Record the final reading on the buret. Repeat this procedure twice more, each time with a fresh 1.0 ml sample of ascorbic acid standard. In a similar fashion, titrate three blanks, each containing 5. o ml of 4% meta phosphoric acid and 1.0 ml of water.

Average the results for each series of measurement. Do the same for the apple juice sample, and the two unknowns. # of Trials Standards Blank Unknown #3 Unknown #4 Apple Juice 1 3.9. 2 4.6 3.0 2.92 4.0. 2 4.4 2.9 2.73 3.8. 2 4.4 3.1 2.9 Average 3.9. 2 4.47 3.0 2.83 Calculations Apple Juice The daily intake of vitamin C should be 70 mg The Apple juice company claims to contain 40% of the daily vitamin C intake.

236 mg of vitamin C in the juice Actual amounts: 2.83 (juice average) -. 2 (blank average) = 2.633. 9 (standard average) -. 2 blank average) = 3.7 (2.63 ml/3.7 ml). 5 mg = . 355 mg of Vitamin C. 355 mg (10 ml/50 ml) = .

071 mg in 10 ml (. 2 (average blank) = (4.27/3.7) (. 5 mg) = . 577 mg of Vitamin Unknown #44.2 -.

2 = (4.0/3.7) (. 5 mg) = . 54 mg of vitamin Conclusion. The apple juice company claims that their apple juice contains 40% of the recommended daily allowance for Vitamin C. However, I have found that the company in actuality only contains less than 3%. Is this an honest mistake or is this yet another example of corporate dishonesty to the consumer.

There may have been error in the experimental procedures. Many people use the lab and the equipment and the chemicals. Contamination of the chemicals used may have easily occurred. There may have been mistakes in pi petting and transferring.