[SiberiaFrogUnit]

Our cheese factory's process examiner of QC team use Volhard method to measure salt content.
And there are two different things compare with Volhard method of the book.

They don't filterate precipitation(AgCl from AgNO3 and NaCl's reaction),
and Add KMnO4 during decomposition of cheese by AgNO3, HNO3.

Frankly speaking,
I think that is so easy that make me feel shame.
But anyone knows about this, please explain to me.

If need more information, reply me anytime.
Thank you.

[Borek]

Please explain whole procedure used.

If you can wet the precipitate with some immiscible liquid, there is no need to filtrate it:

http://www.titrations.info/precipitation-titration-argentometry-chlorides-Volhard

Permanganate is most likely used to destroy the matrix. I am not convinced it is a good idea, as permanganate can oxidize chlorides to chlorine, but perhaps pH never gets low enough for that to happen.

[SiberiaFrogUnit]

sorry, I'm late.

whole process is like as below.

1. take 2 grams of cheese sample into erlenmeyer flask.

2. add 0.1N HNO3 25ml and also add 0.1N AgNO3 25ml.

3. boil flask using by hotplate and make sure that cheese sample melted.
   (after boiling start, normally takes 2minute)

4. after cheese melted, add 7.5%(w/v) KMnO4 10ml into flask on hotplate(still heating).

5. after liquid's color change back to light yellow, add KMnO4 5ml again.

6. wait for color change back to light yellow.

7. after color changed, take out flask from hotplate.

8. cool in room temperature 2~3min.

9. add DW 100ml and wait to flask's temperature going down room temperature.

10. after cooling, add 50%(w/v) FeNH4(SO4)2.12H2O solution 2mL.

11. titration with 0.1N NH4SCN.

thanks.

[Borek]

OK

I don't have much to add to what I wrote earlier.

Have you tried the procedure? Is there a liquid fat left after digestion?