[symby]

I had a sample of cod liver oil tested for rancidity. It is not a clear oil (expected, due to the nature of our extraction), but the lab said it would be ok to use the kreis test.

Having had a look at the Kreis test online, it looks like it passes light through the sample to get a reading. To me, an opaque oil in NOT suitable for this kind of test, as surly light will struggle to pass through, and so false readings may be given.

It has been a long time since doing my chem A levels, and I was hoping someone can help me out here.

Is the kreis test for rancidity suitable for opaque oils? If not, is there are more suitable test?

Thank you all in advance for any light (no pun intended) you can shed on this question.