Stability of nitroaromatic specialty explosives in reversed-phase liquid chromatographic systems

In this study, the stability of 2,4-dinitroanisole, 2,2',4,4',6,6'-hexanitrodiphenylsulfide, 2,3,4,6-tetranitroaniline, 2,4,6-trinitroaniline, 2,4,6-trinitroanisole, and 2,4,6-trinitrochlorobenzene in liquid chromatographic systems was studied under different solvent/eluent conditions. Stock solutions of the explosives were prepared in acetonitrile and diluted with acetone/water, acetonitrile/water, or methanol/water mixtures. Within 48h, these working solutions were repeatedly injected onto a silica column and eluted with acetonitrile/water or methanol/water mobile phases. Under all conditions, 2,4-dinitroanisole was stable, whereas 2,4,6-trinitroaniline was stable only in the methanol/water system. Regarding the other compounds, a more or less pronounced decomposition occurred making the reversed-phase high-performance liquid chromatography analysis difficult or even impossible. The stock standards of 2,4-dinitroanisole and 2,4,6-trinitroaniline were stable for at least 12 months. In addition, some leachate samples were collected from a former explosive factory in Germany and analyzed for nitroaromatic compounds. 2,4,6-Trinitroaniline was detected at concentrations of 60.7-245.5 microg/l.