Dear everyone

There was an unknown peak found in HPLC chromatograph sometimes and it might not come from my analyst. The UV profile of unknown peak indicated two maximum absorptions at UV 202nm and 258nm, minimum at UV 220nm and no absorption above UV 290nm.

Was that unknown peak come from from bacteria or mold?
Because someone told me the specify UV profile just like mold destroyed by methanol.

Thanks for watching.
Debby