Chromatography Forum

The chemists made the compound in pyridine. then they washed it with diluted acetic acid. now they want me to find out the level of residual pyridine (ICH limit 200 ppm) and acetic acid. suppose there may be excess acetic acid, what should I do in sample preparation to make sure I can detect pyridine? should I expect to quantify both pyridine and acetic acid in one method? which column is the best to start with?

sample can be dissolved in DMSO or DMF. other solvents may include acetonitrile, THF and others (not decided yet).

Thank you! Happy Thanksgiving!

I would suggest that you use HPLC for acetic acid (cation exchange) and either HPLC or GC for the pyridine.

Be certain to make the solution basic if you wish to analyze by GC and acidic by HPLC for pyridine.

Both analyses should be straightforward as long as your matrix is not a problem.

best wishes,

Rod