Oils & Fats Adulteration - Chapter – 4 #

4.1.Check the presence of Mineral oils like kerosene oil, Paraffin oil and other petroleum product in eatable and Natural Hair oils. 

Test Method – 1:

Principle: 

The presence of Mineral oil is indicated by the development of turbidity when hot water is

added to a freshly made alcoholic solution of the soap formed by the oil.

·         Take 2 ml of oil sample and add an equal quality of N/2 Alcoholic Potash.

·         Heat in boiling water bath (dip in boiling water) for about 15 minutes and add 10 ml of water. Any turbidity shows the presence of Mineral oil more than 1 % w/w.

Test Method – 2: Holde’s Test

·         Take 25 ml of the alcoholic KOH solution in conical flask and add 1 ml of the sample of oil to be tested.

·         Boil on a water bath using an air or water cooled condenser till the solution becomes clear and no oily drops are found on the sides of the flask.

·         Take out the flask from the water bath, transfer the contents to a wide mouthed warm test tube and carefully add 25 ml of boiling distilled water along the sides of the test tube.

·         Keep on shaking the tube lightly from side to side during the addition.

·         The turbidity indicates presence of Mineral oil, the depth of turbidity depends on the percentage of mineral oil present.

Note: This method is not applicable on high content un-saponifiable value and below 1% content of Mineral oil.

Reference: A.O.A.C 17^th edition 2000, official method 945.102

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