We are using the PORIM method for determination of iodine value for the vegetable oil. Smple weight = 0.3g.
Here are the procedures for Iodine value test:
1. Weight accurately 0.3000g sample into a flask..
2. Add 15ml of solution A into the flask.
[Solution A: 1:1 of acetic acid: cyclohexane]
3.Pipette 25ml of Wij’s solution into the flask. Swirl to mix the reagents.
4. Leave in the dark for one hour.
5. Add 20ml of 10% potassium iodide (10% KI) solution.
6. Add in 100ml distilled water. Shake well.
7. Add in 1ml of starch indicator.
8. Titrate with the standard 0.1N sodium thiosulphate (0.1N Na2S2O3) until dark blue colour disappears.
9. Carry out a blank test under the same condition.
However, we failed to achieve the titration end point. Would you please advise if we have missed any steps? thx
For more information, kindly contact :-
e-mail:
tasenq@mpob.gov.my
Ms Cristalle Ling,
We advise you to contact Dr Tan Yew Ai at e-mail tan
@mpob.gov.my
for the information that you need.
Thank you.
HISAMUDDIN ASPAR
TECHNICAL ADVISORY SERVICES
MPOB