Hi,

I'm working on the analysis of some API's (aminoglycosides) on electrochemical detection.
Everything works fine on my reference substance, but for my pharmaceutical preparation there is a big peak comming from propylene glycol, which is hiding some of my API's and there related compounds.

I tried to change column, pH, temperature, mobile phase, .... but the PG peak is such an overload that it is almost impossible to separate al my component peaks from PG.

Any ideas to get rid of the PG?
I already did some search on SPE and precipitation, but haven't found an adequate answer yet. :?

Ace