A "dilute-and-shoot" method for the Alternaria mycotoxins determination in wheat

Alternaria mycotoxins are the secondary metabolites for which the regulations, as well as the standardization, are yet going to be established by the European Commission and the European Committee for Standardization. This paper describes the possibility to apply a "dilute-and-shoot" method for the determination of tentoxin, alternariol and alternariol monomethyl ether in wheat. The used chromatographic method was liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The strategy involves extraction the samples with the acetonitrile and water mixture (84/16, v/v), followed by the vortexing, centrifugation and filtration before the injection into the LC-MS/MS system. The recovery was assessed by analysis of spiked samples with a mixture of standard solutions of all three mycotoxins at two spiking levels (0.02 and 0.1 mg kg-1) in six replicates. The obtained average recoveries and precisions (expressed as the RSDr, %) for "dilute-and-shoot" method were 76.3% (RSDr of 6.47%) for alternariol, 105.2% (RSDr of 2.16%) for tentoxin, and 86.0% (RSDr of 3.91%) for alternariol monomethyl ether. All the obtained validation data were in accordance with the Commission Decision 2002/657/EC and Commission Regulation (EC) No 401/2006. The main advantages of the present method are the simple and easy sample preparation, along with the high-sensitivity detection.