result and discussion of fecl3 and starch test wi aspirin

Results and discussion

F.

A. Ferric Chloride Test

Prepared ASA

Violet solution with precipitate (+)

Figure. Reaction of FeCl3 with phenol A

B

C

D

E

F

Figure. Results of Ferric Chloride test for the presence of Salicylic Acid Table. Results of Ferric Chloride test for the presence of Salicylic Acid A. Benzyl Alcohol

Immiscible, yellow solution (-)

B. Commercially available ASA

Light yellow solution with precipitate (-)

C. Control (Pure Aspirin)

Clear solution with precipitate (-)

Treatment of a 1% solution of FeCl3 in chloroform with a phenol yields a triaryloxy complex. This reagent is useful for detecting the presence of a hydroxyl group attached directly to an aromatic nucleus; alcohols do not undergo this reaction. Most phenols yield intense red, blue, purple or green colorations in the ferric chloride test. Other functional groups produce color changes with ferric chloride: aliphatic acids give a yellow solution; aromatic acids give a tan precipitate. All phenols do not produce color with this reagent. Highly hindered phenols (such as 2,6-ditertbutyphenol) fail to give positive tests. Enols give a distinctive yellow color when [1] treated with FeCl3/CHCl3/pyridine. Ferric Chloride test is used to check the purity of the prepared aspirin. Because the salicylic acid contains phenol, it is suspected to form a

D. Salicylic Acid

E. Benzoic acid

Violet solution with precipitate (+) Light yellow solution with precipitate (-)

violet solution for its  –OH group will be reacting with the ferric chloride solution.

Table. Results for Starch Test/ Iodine Test

Figure. Reaction of FeCl3 with Salicylic ac id

A. Prepared ASA

Light yellow precipitate (-)

B. Control ASA)

Dark violet solution (+)

(pure

[2]

The salicylic acid together with the prepared

C. Commercially available ASA

Violet precipitate (+)

ASA yields a positive result with a violet solution. This shows that the prepared ASA contains impurities by the presence of salicylic The iodine test for starch is used to determine

acid.

the presence of starch in the prepared aspirin, Benzyl alcohol, benzoic acid, pure aspirin

commercially available ASA, and the control.

(control), and the commercially available ASA yield a negative result. This means that the compounds do not contain phenols. And also the commercially available ASA does not have any salicylic acid content.

Starch is a polysaccharide consisting of glucose units joined together by glycosidic bonds. The chains formed during the condensation reaction are either linear or highly branched molecules. Iodine on its own (small non-polar molecule) is insoluble triiodide

B. Starch Test

in

water.

solution

or

Therefore Iodine

Potassium

dissolved

in

potassium iodide solution is used as a reagent in the test The starch-iodide complex is formed as charge recall electrons are charged particles - is transferred between the starch and iodide ion. The transfer of charge between the starch and the iodide ion changes the spacing between the energy levels/ orbitals. This changes results in the starch-iodide complex absorbing light at a different wavelength than any other species aforementioned resulting in an intense purple [3] color. The prepared ASA yields a negative result, A.

B.

Figure. Starch Test Result

C.

which means it doesn’t contain starch. While

the commercially available ASA and the control yields a positive result which implies the presence of starch. The control should have not

resulted with a positive result because it contains pure aspirin. This may mean that starch was added to the control (pure aspirin). The commercially available ASA yields a positive result because in the pharmaceutical industry, starch is oftenly used as a binder and surfactant. References [1] Chem 4563 Organic Qualitative Analysis Phenols, Enols and Carboxylic Acids-Functional Group Tests. Retrieved August 9, 2014, from http://faculty.swosu.edu/william.kelly/pdf/qo8. pdf

[2] Methodical Instruction for Students of the 1 Course Medical Faculty. Retrieved August 9, 2014, from http://intranet.tdmu.edu.ua/data/kafedra/inter nal/zag_him/metod_rozrobky/en/med/lik/ptn/ biological%20and%20bioorganic%20chemistry/ 1%20course/02.%20Carboxylic%20acids.%20Lip ids.Heterofunctional%20compounds.htm [3] Iodine Test for Starch. Retrieved August 9, 2014, from http://brilliantbiologystudent.weebly.com/iodin e-test-for-starch.html