VIT C_nurel

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[ANALYSIS OF VITAMIN C]

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A. TITLE OF EXPERIMENTAnalysis of Vitamin C

B. DATE OF EXPERIMENTNovember 13rd 2013

C. AIMS OF EXPERIMENTDetermining Precentage of Vitamin C in Sample

D. BASIC THEORYVitamin C, one of the water-soluble vitamin, can form L - ascorbic acid san

dehydroascorbic acid . both have active vitamin C. Vitamin C is synthesized naturally in

plants or animals . Vitamin C is easily oxidized , which can be accelerated by heat , light

, alkali , oxidizing enzymes as well as copper and iron catalysts .

Vitamin C can be absorbed very quickly from the digestive tract, into the

bloodstream and distributed throughout the body. Orange as a source of vitamin C,

with different content in raw fruit and fruit that are old. the older the fruit diminishing

its vitamin C content .

Vitamin C content was determined by iodometric, where vitamin C reduces I2

become I-. The end point of the titration is determined blue starch . Daat dihtung levels

of vitamin C as follows :

Precentage of Vit C Precentage of Vit C

Peer

Pyrus communis pears or fruit that is still

included in the Apple family. Several species of

pear tree produces good to eat fruit because it

contains a lot of water and sweet. Not only

tastes delicious, Pears also brings many health

benefits for our bodies know.


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Pears are a good source of fiber for the body. Each 100 gram Pears contains 3.1

grams of fiber or 8% of the amount of fiber that your body needs. Eating Pears

regularly efficacious for preventing colon cancer. This is because the Pears are rich infiber, antioxidants, minerals and vitamins, which are necessary for optimal health.

Level of antioxidant power (ORAC value) in Pears is 2,941 umol TE/100 g. High levels

of antioxidants which is what makes it able to prevent you from cancer.

Most of the fibers in the Pears are non-soluble polysaccharides (NSP), which serves

as a good bulk laxative in the gut. Additionally, gritty fiber content binds toxins and

cancer-causing chemicals in the colon, protecting mucus membranes. In addition, thepear is one of a very low calorie fruit provides 58 calories per 100 grams. Only some

parts of the day in the diet can bring significant reductions in body weight and blood

levels of LDL cholesterol.

Pears contain vitamin C amount of about 7% per 100 grams. Pears to be source of

plant-based flavonoid antioxidant nutrients like beta-carotene, lutein and zea-xanthin.

These compounds, along with vitamin C and A, help the body avoid harmful freeradicals. In addition, Pears are also a source of minerals such as iron, potassium,

magnesium and B-complex vitamins such as folate, riboflavin and pyridoxine (vitamin

B-6).

Iodometry Titration

Iodometry is one of the most important redox titration methods. Iodine reacts

directly, fast and quantitively with many organic and inorganic substances. Thanks to

its relatively low, pH independent redox potential, and reversibility of the

iodine/iodide reaction, iodometry can be used both to determine amount of reducing

agents (by direct titration with iodine) and of oxidizing agents (by titration of iodine

with thiosulfate). In all cases the same simple and reliable method of end point

detection, based on blue starch complex, can be used.

Reversible iodine/iodide reaction mentioned above is


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E. TOOLS & MATERIALS

TOOLS MATERIALS

Mortar

Graduated cylinder

Erlenmeyer

Buret

I2solution 0.001 N

Amylum 1% solution

Peer

F. PROCEDURE

4 grams fruit sample

- Broke with mortar until got sturry

-Entered into volumetric flask 50 ml

-Added aquadest

-Allowed for 15 minutes and shaked

Colorless solution

Sample solution

-Take 10 ml

-Entered into erlenmeyer flask

-Added amylum 1% (3drops)

-Added 20 ml aquadest

-Titated iodium standart solution 0.001N


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G. OBSERVATION

PROCEDURE HYPOTHESIS RESULT CONCLUSION

C6H8O6C6H6O6+ 2H++ 2e

I2+ 2eI-

The precentage vitamin C in peer:

4.20 mg/100 g of sample or 7%

Before

Amylum = colorless

I2 = yellowish

Pear solution = colorless

After

Amylum + pear solution= colorless

After titrated with Iodyum 0.001N

the color become blue fade.

Result of titration

V1(I2) = 3.6 ml

V2(I2) = 3.4 ml

V3(I2) = 3.4 ml

The average of

vitamin C in pear is

37.464 mg/100 g of

sample

%vit C in sample

= 0.037 %

4 grams fruit sample

- Broke with mortar until got sturry

-Entered into volumetric flask 50 ml

-Added aquadest

-Allowed for 15 minutes and shaked

Colorless solution

Sample solution

-Take 10 ml

-Entered into erlenmeyer flask

-Added amylum 1% (3drops)-Added 20 ml aquadest

-Titated iodium standart solution

0.001N


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H.ANALYSIS AND DISCUSSION

Determination of vitamin C in the samples was done by several stages as follows:At this time experiment aimed to determine the levels of vitamin C in the sample, the

sample used is pear fruit, and then pear fruit peeled and smoothed by using a mortar to

reduce the particle. After feeling smooth pear weighed as much as 4 grams. And slurry

or extract obtained put in 50-mL volumetric flask and then added distilled water to

mark boundaries and wait up to 15 minutes while shaken, and the aim of settling the

flask is shaken to dissolve the vitamin C contained in pear fruit in distilled water, and for

15 minutes so that vitamin C can be dissolved perfectly.Then 10 mL of the filtrate was taken and put into erlenmeyer and added 3 drops of

1% starch and 20 mL of distilled water which is then titrated with a standard solution of

I2 0.001 N. Iodine has the properties can oxidize vitamin C, and vitamin C reduce I2 to I-

so by titrating the sample with I2 will be able to determine the levels of vitamin C

contained in the sample, and the function rather than the addition of starch is an

indicator of where the endpoint will be in get blue. And the reaction that occurs is:

C6H8O6C6H6O6+ 2H++ 2e

I2+ 2eI-

Many levels of vitamin C in the sample can be seen from the number of I2 required in the

process to reach the titration endpoint where I2 is needed more and more the more the

level / amount of vitamin C in the sample. This indicates that the length of oxidized

vitamin C with increased content of vitamin C in the sample. I2 volumes and the results

obtained are as follows: V1 = 3.6 mL; V2 = 3.4 mL; V3 = 3.3 mL. Having in mind the

volume of I2 is obtained, it can be calculated levels of vitamin C in the sample

(calculations in Appendix) and the levels of vitamin C results obtained on each - each

titration is 39.283 mg; 37.100mg; 36.009 mg with - average = 37.464 mg / 100 g or 0.037

g/100g .

After determining the levels of vitamin C and then calculate the percentage of vitamin C

(calculations in Appendix), and obtained 0.037%. In theory the levels of vitamin C in the

sample was 4.02 g/100 g and the percentage of 7%.


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Our results are still far less than the levels of vitamin C in theory because at the time it

maybe rudimentary titration to reach the titration end point so that the volume of I2

obtained less valid

I. CONCLUSIONThe average of vitamin C in pear is 37.464 mg/100 g. And the presentage of 0.037%.

REFFERENCES

Anonim A.2011. Pear.http://Wikipedia.org (diakses pada hari Rabu, 13

November 2013, Pukul11:00 WIB)

Chaerani, Annisa Nurul. 2010.Penentuan Adanya Vitamin C Secara Kualitatif. Cimahi :

Sekolah Tinggi Ilmu Kesehatan.

Lehninger AL. 1982. Dasar Dasar BiokimiaJilid I. Maggy Thenawijaya, penerjemah.

Jakarta: Erlangga. Terjemahan dari: Principles of Biochemistry.

Tim. 2013. Petunjuk Praktikum Biokimia I. Surabaya: Unesa Press.

ANSWER & QUESTION

ATTACHMENT

1. Determine the precentage of vitamin C in sample!Known : N I2= 0,01 N

Ascorbat acid in 0.01N=0.88 mg

Diluting formula : N1x V1= N2x V2

0,01 N x 5 mL = N2x 50 mL

N2= 0.001 N

Volume of I2 :

V 1 = 3.6 mL

V 2 = 3.4 mL

V 3 = 3.3 mL


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The calculation of precentage vit C :

Known : weigh of sample = 4.03 g = 4030 mg

Volume sampel = 10 ml

()

1st experiment = 3.6 mL

2nd experiment = 3.4 mL

3rd experiment = 3.3 mL

The average of Vitamin C

% Vitamin C in sample


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2. Draw the structure of Vitamin C!

3. Mention disease that caused deficiency of vitamin C1. irritability

2. Pain in lower leg

3. Pseudoporolisis lower limbs, upper limbs while jarangterserang

4. mild bleeding

5. tooth loss, sores on the gums, wounds difficult to heal and easily broken bones

4. Mention fruit foods containing Vitamin C!

1. Ubi: contains 35.3 mg of vitamin C.

2. Cantaloupe: contains 49.2 mg of vitamin C.3. Kiwi: contains 137.2 mg of vitamin C

4. Strawberry: contains 147 mg of vitamin C

5. Papaya: contains 157 mg of vitamin C

6. and so on

5. Mention the important role of vitamin C in the body!

1. Best antioxidants

2. Lowering the Risk of Heart Disease3. Lowering Cholesterol Levels

4. Lowering Blood Pressure

5. Improve Immune System

6. healing Wounds

7. Potent Against Allergies

8. Caring for Your Skin


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PICTURES

Filtering process of ekstrac pear

Pear solution before titrated with I2

Titration process

Pear solution after titrated with I2

the color become more black than before


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