Characterization of Ephedrine as Illegal Methamphetamine Precursors Based on δ15N, δ13C, and δ2H Isotopes: Their Application for Methamphetamine Profiling in Indonesia
Objectives: The δ15N, δ13C, and δ2H profile of the ephedrine as a methamphetamine precursor is a fingerprint to describing its origin. The origin of the precursor is one of the supporting data in methamphetamine profiling. In this research, the isotope profiles of natural, synthetic, and semi-synthetic clusters of ephedrine were established. These clusters were applied to predict the origin ephedrine from seized methamphetamine samples in Indonesia. Methods: The isotope profiles of methamphetamine and its precursor were clustered in two steps. Initially, ephedrine and pseudoephedrine from various of the origin were prepared, and then the methamphetamines were synthesized from 4 samples ephedrine of known origin using Emde and Moscow routes. Emde is a method mostly found in Indonesia, and also Moscow as a comparison. Elemental Analyzer-IRMS were used to analyze isotope abundance ratio in order to establish the natural, synthetic, and semi-synthetic clusters. This study was carried out to a total of 20 methamphetamine samples to identified the origin of precursors. Results: The results showed that the isotope profiles of ephedrine and pseudoephedrine formed groups based on the origin. And the isotope profiles of methamphetamine were similar to those of the precursors. Conclusion: The δ15N, δ13C, and δ2H isotope clusters of ephedrine/pseudoephedrine can be applied to seized methamphetamine samples to characterize the origin of the precursor.