Detection of trace levels of trichothecene mycotoxins in human urine by gas chromatography-mass spectrometry.

A method is described for the simultaneous detection of the trichothecene mycotoxins T-2, HT-2, T-2 tetraol, diacetoxyscirpenol, 15-monoacetoxyscirpendiol, scirpentriol, nivalenol and deoxynivalenol, in human urine. Samples were extracted from Clin Elut columns and cleaned up using reversed-phase Sep-Pak C18 cartridges. Trichothecenes were derivatised as their heptafluorobutyryl esters, and detected by gas chromatography-mass spectrometry-selected-ion monitoring using electron impact ionisation. The method was validated by the analysis of 22 urine samples, spiked and submitted "blind" for analysis by another laboratory. An alternative gas chromatography-mass spectrometry method using negative ion chemical ionisation is also described and a preliminary comparison of the two methods made. The methods enabled levels down to 1 ppb to be detected, with confirmation of identity at levels between 2 and 5 ppb, depending on the toxin.