Isotopic labelling used to study explosive compounds

Ana Racoveanu is a scientist synthesizing energetic compounds with isotopic labels, a rare feat in the nuclear security enterprise.

Isotopic labeling uses various stable isotopes of given elements in the place of their most common isotope throughout a chemical reaction. The different properties of the non-standard isotope allow its progress through the reaction to be tracked, providing insight into the mechanics of the reaction itself. The goal of creating isotopically labeled energetic materials is to help make munitions safer to handle and use.

"This work unlocks a unique method of examining the science of energetic materials. It is a tracer method allowing discovery of reaction networks of energetic materials during performance as well as in environments not encountered during normal operations or abnormal environments," said Racoveanu.

Previously, making stable isotopically labeled energetics has been rare due to the prohibitive expense of starting materials. Cheaper labeled ingredients and synthetic methods for energetic materials have helped make isoptically labeling energetics more available, but their quantity is still limited by expense.

"The main challenge in stable isotopic labeling in general is the very skillful execution of synthesis of all the steps involved. Failure during the synthetic process is solvable, but at a very high cost, sometimes unaffordable. This is valid for the synthesis of isotopically labeled energetic materials, as well. Also, designing alternate pathways for making the labeled endpoints may have to be done because the appropriate labeled starting material is not available," Racoveanu said.

The National Nuclear Security Administration (NNSA) and laboratories under its umbrella, such as Sandia National Laboratories, are interested in this work and have reached out for help labeling volatile compounds.