Q. Detect the presence for sesame oil and linseed oil?

To detect the presence for sesame oil, linseed oil, argemone oil, mineral oil and hydrocyanic acid.

After undertaking this activity, you will be able to:

• discuss the various adulterants in oils/fats, and

• qualitatively determine their presence in the given samples.

Principle

You are already aware of the principles involved in the detection of adulterants. Refer to sub-section 4.4.6. Write the principle involved for each oil in the space provided.

Materials Required

1) One sample of oil (sample 1) and one sample of fat (sample 2)

2) Hydrochloric acid - fuming, relative density 1.19

3) Furfural solution - 2 % solution of furfural distilled not earlier than 24 hours. The reagent is stable up to 3 months if kept in the refrigerator

4) Chloroform

5) Liquid bromine

6) Rectified spirit

7) Ether

8) FeCl3 solution - 10%

9) Alcoholic caustic potash solution- 0.5 N

10) Picric acid paper - soak a filter paper (Whatman no. 1 or equivalent) in a saturated aqueous solution of picric acid, draining excess liquid and drying the dyed paper in air. The paper should be prepared freshly before use.

11) Tartaric acid solution - 10 % (m/v)

12) Sodium carbonate solution - 5% (m/v)