This European Standard specifies a method for the determination of five Alternaria toxins in wheat, tomato juice and sunflower seed samples by liquid chromatography tandem mass spectrometry (LC-MS/MS). The method includes the analysis of Altenuene (ALT), Alternariol (AOH), Alternariol monomethyl ether (AME) in the range of 1 µg/kg to 100 µg/kg, and Tentoxin (TEN) in the range of 5 µg/kg to 500 µg/kg, and Tenuazonic acid (TEA) in the range of 10 µg/kg to 1000 µg/kg.