Q. Determine the impurities in the sample of oil?

After conducting this activity, you will be able to:

• determine impurities such as total dirt and organic dirt in the given sample of oil,

• differentiate between total dirt and organic dirt, and

• check whether any given samples of oils/fats conforms to the standard.

Principle

Total impurities can be regarded as total dirt and organic dirt. The materials required and the procedure for determination of total dirt and organic dirt is presented separately next.

A) For Determination of Total Dirt

Materials Required

Sample of Oil/fat

Oven-electric, maintained at 100 ± 1°C.

Dessicator

Weighing balance

Filter paper

Procedure

Carry out the experiment following the procedure enumerated herewith:

1) Take 30-50 g of oil or fat at a temperature below 60^ºC.

2) Filter through a filter paper previously dried in the oven at 105ºC and weighed.

3) Extract the filter paper containing the impurities with light petroleum ether of grade (boiling pt. 40ºC - 60ºC). In this step, basically pour the ether onto the filter paper.

4) After complete extraction, dry the filter paper and its contents in the oven at 98^º C-100^ºC till a constant weight.