TATP isotope ratios as influenced by worldwide acetone variation

Isotope ratio analysis has been shown to discriminate samples of forensic interest and to link many synthesized and natural materials to their precursors when traditional chemical and physical analyses cannot. Successful application of stable isotope analysis to chemicals of interest requires a background of likely variations in stable isotope ratios; often, this background population can be generated from analysis of possible precursors and the relationships of stable isotopes of precursor(s) to product(s), which may depend on synthesis techniques. Here we measured the carbon (¹³C/¹²C) and hydrogen (²H/¹H) isotope ratios of the oft-illicitly manufactured explosive triacetone triperoxide, TATP, and one of its precursors, acetone. As acetone is the sole source of carbon and hydrogen to TATP, a survey of acetone from 12 countries was conducted to explore the breadth of ¹³C/¹²C and ²H/¹H variation in the precursor, and therefore, its product. Carbon and hydrogen isotope ratios were measured using continuous flow isotope ratio mass spectrometry (IRMS) techniques. We observed greater ranges in both C and H isotope ratios of acetone than previously published; we also found that country-of-purchase was a large contributing factor to the observed variation, larger than acetone grade and brand. Following clandestine production methods, we observed that the stable isotope ratios of TATP retained the stable isotope signatures of acetone used in synthesis. We confirmed the robustness of TATP carbon isotope ratios to both recrystallization and time-dependent sublimation, important considerations when faced with the task of practical sampling of potential unexploded TATP from a crime scene.