A simple determination of cyclopiazonic acid by HPLC is elucidated. Th
e zinc cation in the mobile phase and indomethacin as an internal stan
dard made quantitation higher and peak identification of cyclopiazonic
acid easier. In the combination with a TLC analysis, production of cy
clopiazonic acid by some species of aspergilli could be analyzed both
in a liquid culture and in a solid culture on wheat bran without a pri
or clean-up operation.