[Duongtrung30]

I'm working for a pharmaceutical company. We use KF volumetric titratior
to determine water in raw materials and products. We are currently using the
Metter toledo t7 device and 2 solutions of combititran 5 (lodine, imidazole,
2-methylimidazole) and combiMethanol for this test. I have 2 questions as
follows:
1. Where is sulfur dioxide dissolved? (because the labels of the above two
solutions do not mention sulfur dioxide),
2. If using 2 different solvent bottles, is this one-component reagent or
two-component reagent and why?

[Hunter2]

The SO2 is dissolved in the same bottle, where the Iodine, Methanol and Imidazole is in.
SO2 reacts with I2 only when get wet.

[Duongtrung30]

I know that, but the labels of Combititran 5 and CombiMethanol do not list SO2

[Hunter2]

Refer to  MSDS or use your nose carefully. Also the iodine gives brown colour.