Although nanotechnology advancements should be fostered, the environmental health and safety (EHS) of nanoparticles used in technologies must be quantified simultaneously. However, most EHS studies assess the potential implications of the free nanoparticles which may not be directly applicable to the EHS of particles incorporated into in-use technologies. This investigation assessed the aquatic toxicological implications of copper oxide (CuO) nanospheres relative to CuO nanorods used in nanoenergetic applications to improve combustion. Particles were tested in both the as-received form and following combustion of a CuO/aluminum nanothermite. Results indicated nanospheres were more stable in water and slowly released ions, while higher surface area nanorods initially released more ions and were more toxic but generally less stable. After combustion, particles sintered into larger, micrometer-scale aggregates, which may lower toxicity potential to pelagic organisms due to deposition from water to sediment and reduced bioavailability after complexation with sediment organic matter. Whereas the larger nanothermite residues settled rapidly, implying lower persistence in water, their potential to release dissolved Cu was higher which led to greater toxicity to Ceriodaphnia dubia relative to parent CuO material (nanosphere or rod). This study illustrates the importance of considering the fate and toxicology of nanoparticles in context with their relevant in-use applications.

PURPOSE:High performance liquid chromatography (HPLC) and gas chromatography (GC) are most commonly used for the measurement of the insensitive munition constituent 2,4 dinitroanisole (DNAN). These methods require investments in equipment, supplies, labor, and training. A screening method was investigated and validated as a low-cost alternative for ecotoxicology testing to quickly quantify DNAN in solution using commonly available instrumentation. This new method uses a spectrophotometer, measuring absorbance in the ultraviolet range. Simple standard curves are employed to determine concentrations of DNAN. Consistently accurate concentrations were validated by HPLC and GC methods. Additionally, the presence of DNAN breakdown products can be observed. INTRODUCTION:Insensitive munitions containing the constituent 2,4-dinitroanisole (DNAN) are being pursued as safer, more stable alternatives to traditional munitions such as trinitrotoluene (TNT) (Boddu et al. 2009;Kennedy et al. 2013). Current methods for quantifying DNAN in solution require high performance liquid chromatography (HPLC) or gas chromatography (GC). Although these techniques are effective, a reliable, higher throughput, lower-cost, and more accessible screening detection method was desired for ecotoxicology testing. Such a method would benefit laboratory toxicological assessments, which require stock concentration validation, verification of serial dilution concentrations, and a means to rapidly assess compound stability over time.

There is an increasing likelihood of interactions between nanomaterials and munitions constituents in the environment resulting from the use of nanomaterials as additives to energetic formulations and potential contact in waste streams from production facilities and runoff from training ranges. The purpose of the present research was to determine the ability of nano-aluminum oxide (Al(2)O(3)) and multiwalled carbon nanotubes (MWCNTs) to adsorb the munitions constituents cyclotrimethylenetrinitramine (RDX) and tungsten (W) from aqueous solution as a first step in determining the long-term exposure, transport, and bioavailability implications of such interactions. The results indicate significant adsorption of RDX by MWCNTs and of W by nano-Al(2)O(3) (but not between W and MWCNT or RDX and nano-Al(2)O(3)). Kinetic sorption and desorption investigations indicated that the most sorption occurs nearly instantaneously (<5 min), with a relatively slower, secondary binding leading to statistically significant but relatively smaller increases in adsorption over 30 d. The RDX sorption that occurred during the initial interaction was irreversible, with long-term, reversible sorption likely the result of a secondary interaction; as interaction time increased, however, the portion of W irreversibly sorbed onto nano-Al(2)O(3) also increased. The present study shows that strong interactions between some munitions constituents and nanomaterials following environmental release are likely. Time-dependent binding has implications for the bioavailability, migration, transport, and fate of munitions constituents in the environment.