Identification of FC/TA-891 and its metabolite, FCE22101 by high performance liquid chromatography - Atmospheric pressure chemical ionization mass spectrometry using bromoform

A new identification method was developed for a heat-unstable antibiotic, FC/TA-891, which belongs to the penem type antibiotic, and its active metabolite (FCE22101). High-performance liquid chromatography (HPLC) - atmospheric pressure chemical ionization mass spectrometry (APCI-MS) was employed for their identification. As an ionization acceleration solvent, bromoform, which was added to the mobile phase in HPLC, was found to give clear and stable adduct ions, [M + Br](-) for FC/TA-891 and FCE22101, compared to chloroform. These adduct ions can be clearly distinguished from other ions due to their isotopical ratio (1:1), leading to an easy identification of both compounds.