Carbon and nitrogen stable isotopes as indicative of geographical origin of marijuana samples seized in the city of São Paulo (Brazil)

• Published in: Forensic science international 2007-03, Vol.167 (1), p.8-15
• Main Authors: Shibuya, Elisa K, Sarkis, Jorge E.S, Negrini-Neto, Osvaldo, Martinelli, Luiz A
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Carbon; Cocaine; Drug sourcing; Forensic medicine; Forensic sciences; General aspects; Investigative techniques, diagnostic techniques (general aspects); Isotopes; Linear discriminant analysis; Marijuana; Medical sciences; Nitrogen; Pathology; Public health. Hygiene; Public health. Hygiene-occupational medicine; Stable isotopes
• ISSN: 0379-0738; 1872-6283
• DOI: 10.1016/j.forsciint.2006.06.002

Abstract The drug trafficking is one of the most serious problems related to the Public Safety in Brazil, especially in the most populous areas of the country, as is the case of the city of São Paulo. In this work, it was developed a methodology that can help tracking the traffic routes of marijuana samples seized in the city of São Paulo, based on stable carbon and nitrogen isotopes, which are related to the climate and plant growth conditions. A model to classify the origin of unknown samples was built using linear discriminant analysis based on about 150 samples apprehended in the main producing regions of the country. Results for 76 samples seized in the city of São Paulo showed that most of them were cultivated in a humid region with the same origin as those from Mato Grosso do Sul. The provenance of 13 outliers samples from Northeast region (an important producing region) also were evaluated and some of them presented same profile of those from Mato Grosso do Sul, pointing to the existence of the traffic routes between the Northeast and Midwest region, probably as a consequence of the intensive field raids by Brazilian Federal Government since 1999.