REDOX titration sulfur dioxide content in wine!!!!!! HELP ! URGENT

[aronno]

In this titration i had to detirmine the SO₂ content in wine.

I₂ + SO₂ + 2H₂O ---> SO₄^2- + 2I^- +4H⁺
(i know states are misssing!!)
the sample is titrated with iodine solution...
iodine in burrete..... etc.


the question is;
The conc. i got for Sulfur dioxide was 103ppm however it was lower  than the manufacteres specifications
what could have lead to a dec. in conc.

also if the SO₂ evapourates what effect does it have on the conc.!!!!
and what if the Iodine evapourates what effect does that have on the conc.!!!!
 

[Mao]

The conc. i got for Sulfur dioxide was 103ppm however it was lower  than the manufacteres specifications
what could have lead to a dec. in conc.

also if the SO₂ evapourates what effect does it have on the conc.!!!!

answered your own question there if it is exposed to atmosphere, SO2 evaporates, hence the amount you measure would be less than what is stated by manufacturer.

if Iodine evaporates, then the titre would have been too high, and the calculated concentration of SO2 would be higher than actual

[aronno]

MAO ur r the BEST DUDE!! thanks!