Boyu Ma

The crystal morphology of high energetic materials plays a crucial role in aspects of their safety performance such as impact sensitivity. In order to reveal the crystal morphology of ammonium dinitramide/pyrazine-1,4-dioxide (ADN/PDO) cocrystal at different temperatures, the modified attachment energy model (MAE) was used at 298, 303, 308, and 313 K to predict the morphology of the ADN/PDO cocrystal under vacuum and ethanol. The results showed that under vacuum conditions, five growth planes of the ADN/PDO cocrystal were given, which were (1 0 0), (0 1 1), (1 1 0), (1 1 −1), and (2 0 −2). Among them, the ratios of the (1 0 0) and (0 1 1) planes were 40.744% and 26.208%, respectively. In the (0 1 1) crystal plane, the value of S was 1.513. The (0 1 1) crystal plane was more conducive to the adsorption of ethanol molecules. The order of binding energy between the ADN/PDO cocrystal and ethanol solvent was (0 1 1) > (1 1 −1) > (2 0 −2) > (1 1 0) > (1 0 0). The radial distribution function analysis revealed that there were hydrogen bonds between the ethanol and the ADN cations, van der Waals interactions with the ADN anions. As the temperature increased, the aspect ratio of the ADN/PDO cocrystal was reduced, making the crystal more spherical, which helped to further reduce the sensitivity of this explosive.

A modified calibration curve method based on the combination of standard addition and traditional calibration curve methods was employed for the quantification of Prussian blue nanoparticles in rats in the presence of endogenous iron interferences. The assay was performed using inductively coupled plasma – optical emission spectrometry (ICP-OES) with yttrium as the internal standard, and validated in biomatrices including liver, heart, kidneys, lungs, spleen and whole blood. For the liver tissue, the intra-day and inter-day precision were 7.84% or less, and the accuracy was between 99.88% and 102.37%. For kidneys, lungs, heart, spleen, and blood, at each exo-additive level from 0.4 to 3.2 µg/mL, the intra-day accuracy was between 98.74% and 102.09%, and the intra-day precision was 6.17% or less. For the addition of no analyte, the intra-day accuracy was between 96.42% and 107.52%, and the intra-day precision was 15.67% or less. The stability was investigated at 25 °C for 24 h and 4 °C for 15 days in liver standard addition samples, and no significant degradation occurred under these conditions. This method was successfully applied to the preliminary pharmacokinetics and tissue distribution study of Prussian blue nanoparticles in rats. This approach may also be applied to the quantification of other ferruginous materials in the biological matrices with endogenous iron.