USA. New discovery helps authorities pinpoint origin of heroin
Researchers at Florida International University's International Forensic Research Institute (IFRI) have zeroed in on a unique component of heroin that could pinpoint where it was grown, giving authorities a new tool to potentially disrupt the nation's opioid crisis.
(...) Researchers needed to find something unique in the heroin itself that could not be masked or eliminated in order to determine its point of origin – something the typical manufacturer wouldn't know to look for or care to mask. They zeroed in on the ratio of radiogenic strontium isotopes, which are naturally occurring in bedrock. Strontium isotopes can be found in different ratios among geographic regions depending upon the nature of geologic formation.
Using heroin samples of known geographic origin provided to them by the DEA, researchers were able to measure ratios of strontium isotopes in samples known to come from the four distinct regions. (phys.org, 28.09.2017)
https://phys.org/news/2017-09-discovery-authorities-track-heroin.html