Environmental Analysis of Aqueous 3-Nitro-1,2,4-Triazol-5-One (NTO) by Ion Chromatography with Conductivity Detection
Engineer Research and Development Center Hanover United States
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The newly fielded insensitive high-explosive compound 3-nitro-1,2,4-tria-zol-5-one NTO is mobile in the environment due to its high water solubility and low affinity for soils. The weak acidity of NTO pKa 3.67 presents a challenge to environmental analysis by high-performance liquid chromatography but enables direct separation by ion chromatography IC. Here we developed an IC method for NTO in natural water, soil, and post detonation residue. A gradient potassium hydroxide separation effectively resolved the inorganic anions Fbar, C1bar, NO2bar, Brbar, SO42bar, NO3bar, and PO43bar and NTO in 18 minutes. Suppressed conductivity of aqueous NTO was linear from 10 microgramL to 10 mgL with a detection limit of 3 microgramL and quantitation limit of 9 microgramL. Recoveries of NTO-spiked natural water samples were 93 percent-118 percent at concentrations of 30, 100, and 500 micrometerL. Recoveries of NTO-spiked soil samples were 91 percent- 114 percent using deionized water DI extraction. NTO was completely recovered with DI-extraction in two post-detonation residue samples of IMX-101 but only partially recovered 58 percent and 69 percent in two higher-concentration residues, potentially due to incomplete dissolution of the energetic particle matrix. These results support IC for confirmation analysis of environmental samples and for screening nat-ural water samples while simultaneously analyzing inorganic ions.
- Ammunition and Explosives
- Physical Chemistry
- Environmental Health and Safety