Presence of four Fusarium mycotoxins and synthetic material in 'yellow rain'. Evidence for the use of chemical weapons in Laos.

Analysis of a 'yellow rain' sample by selected ion monitoring revealed the presence of three trichothecenes: T-2 toxin, diacetoxyscirpenol and 4-deoxynivalenol in concentrations of at least 48, 42 and 58 ppm, respectively. The concentration of zearalenone, another Fusarium mycotoxin, was estimated to be at least 265 ppm. Evidence for a formulation which contained polyethylene glycol was also obtained.