Determination of beauvericin and four other enniatins in grain by liquid chromatography–mass spectrometry

A method is described using LC–MS–MS for the detection of five different enniatins in grain. The method involves extraction of the fungal secondary metabolites using acetonitrile–water and quantification using LC–MS–MS with atmospheric pressure chemical ionisation, without further treatment of sample extracts. The selected ion reaction of [M + NH4]+ to [M + H]+ was utilised in the specific detection of the compounds. Mean recoveries (n = 5–12) of enniatins from spiked grain samples over a period of six months were 99–115%, 86–131%, 97–113%, 73–100% and 78–114% for beauvericin, enniatin A, A1, B and B1, respectively. The limits of detection were 3.0 μg/kg for beauvericin, enniatin A, B and B1 and 4.0 μg/kg for enniatin A1, which corresponds to on-column detection limits of 7.5 pg and 10 pg, respectively.