Quantitative Analysis of Thermostable Explosive Compounds by Combined Liquid Chromatography/Tandem Mass Spectrometry

A method for quantitative determination of thermostable explosive compounds is described. This method uses a Perkin Elmer Sciex API III triple-quadrupole mass spectrometer equipped with an atmospheric-pressure ion source, as a detector for liquid chromatography. The explosives were dissolved in dimethylformamide and the quantitative analysis was performed by combined liquid chromatography/tandem mass spectrometry using a phenyl column. Selected reaction monitoring experiments were performed by setting the first quadrupole to pass the [M-H]− or [M+acetate]− ions of a selected explosive, while simultaneously setting the third quadrupole to pass its most characteristic fragment ion. An extensive statistical analysis of results was carried out, which showed a linear response between 0.8 ng and 12.8 ng for hexanitrostilbene, between 0.4 ng and 6.4 ng for hexanitrodiphenylamine, and between 0.1 ng and 1.6 ng for tetranitroacridone. Detection of these compounds with an intra-assay relative standard deviation (RSD) between 0.53% and 5.79% and an inter-assay RSD between 0.08% and 6.61% was obtained with this method. Accuracy, expressed as percentage error, was always better than 7%.