[matso]

Hi,
New to these boards.  I am working on an interesting problem and was looking for some suggestions.  I am looking to determine the concentration of the degradation acids (primarily glycolic and formic) in a sample of used heat transfer solution (60:40 blend of monoethylene glycol).  Ideally, I would like to be able to differentiate between the different organic degradation acids, however I am looking to avoid IC due to certain budgetary constraints.  I was wondering if any of you could suggest a clever method for determining the concentration of these degradation acids separately.  There are likely going to be a lot of contaminants in the solution including iron and copper ions and corrosion byproducts, chloride ions, and various hydrocarbons.  I realize I can determine the total acidity by performing an acid/base titration with an indicator.  A contact of mine recently suggested that the oil and gas industry used (perhaps still uses) potentiometric titration to determine the concentration of specific acids.  I have done a little research, and unless there is a specific method I am missing, I can only see being able to calculate the total acidity.  Is there some advantage of using potentiometric titration that I am missing? Or am I going to get the same information as I would from an acid/base titration w/ an indicator?  Thanks for your help.

[Borek]

pKa difference is way too small (3.75 vs 3.83) to separate them by titration, probably even in non-aqueous solvent. As far as I know potentiometric titration won't change it.

No ideas at the moment.