Water Content in Edible Oils and Fats

The applications gives the method for determination of water content in various edible oils like sunflower oil, peanut oil, olive oil etc. and fats like margarine using  volumetric  Karl Fischer titration. The titration is monitored by a double platinum redox electrode (voltametric indication).

Background:

Water is an inevitable contaminant in both fresh oil (trace levels) and in frying oil (at high levels) being introduced by food. According to Food    Standards    Committee, the  moisture  content  of  the  oil  is  of  great importance  for  many  scientific,  technical  and  economic reasons. Low moisture content is a requirement  for  long  storage  life . The maximum limit of moisture in edible  oils  according  to  APCC  should  be  0.1%-0.5%.

To determine the exact content of water Karl Fischer titration is used. (To know more about Volumetric Karl Fisher Titration, watch video here)  As there is very little water content in edible oils, a sample size of at least 1.0 g has to be used to achieve accurate result and a reasonable reproducibility.

Reaction:

CH₃OH + SO₂ + 3RN + I₂ + H₂O ------> (RNH)SO₄CH₃ + 2(RNH)I

The application gives a completely automated method using autotitrator along with titration autosampler.