3-Demethyl Colchicine, 25mg

N-(4-chloro[13C6]phenyl)-N'-(3,4-dichloro[13C6]phenyl)[13C]urea , 1.2ml x 50ug/ml, methanol

Diethyleneglycol-monobutylether, 1000µg/ml in MeOH

PAH Standard