Mass Spectral Investigations on Toxins. 9. Application of Liquid Chromatography/Mass Spectrometry Techniques for the Detection and Quantification of Macrocyclic Trichothecenes in Brazilian Plant Samples

摘要

Trichothecenes are toxic, fungal metabolites that have been associated with human health hazards, farm product, live stock, and other animal losses for decades. Allegedly, these metabolites were also used as chemical warfare agents. Recently, the growth of trichothecene-producing fungi has been detected also in U.S. urban environments. Thus, the development of rapid, specific, sensitive, and accurate methods for analyzing these toxins in environmental, agricultural, and biological samples has become vital. The large number of trichothecenes present and their polar and labile properties pose a great challenge in developing a common methodology to analyze all the derivatives of interest. Thermally labile, polar, toxic roridins and biologically active baccharinoids were separated over a reverse phase, high-performance liquid chromatographic column and effectively ionized under thermospray ionization conditions. The mass spectra indicated the formation of corresponding molecular ion-ammonium adducts in great abundance. Experiments designed for monitoring specific ions of these analytes at predesignated intervals were used to accurately analyze these macrocyclic trichothecenes in real, crude samples. A synthetically modified macrocyclic trichothecene, 8-ketoverrucarin A, was used as the internal standard for detecting and quantifying these compounds. The minimum detectable limits were from 1 to 2 nanograms.