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 microg/kg for beauvericin, enniatin A, B and B1 and 4.0 microg/kg for enniatin A1, which corresponds to on-column detection limits of 7.5 pg and 10 pg, respectively.