14C analyses quantify time lag between coca leaf harvest and street-level seizure of cocaine

摘要

Measurements were made on the natural abundance 14C content (Δ 14C) of cocaine specimens seized between 2003 and 2009. The objective of this study was to determine the extent to which Δ 14C analyses could quantify the "age" of recent cocaine seizures. Here "age" of a seized cocaine specimen is defined as the time period between when a coca leaf was harvested in South America and its seizure as cocaine at either the international or domestic street levels. Based on Δ 14C analyses of seizure specimens, there were no statistically significant differences in the ages of domestic cocaine HCl and cocaine base specimens seized on the streets in different locations across the United States. Between 2007 and 2009, the average age of a street-level cocaine seizure in the United States was 24.6±1.1months. Cocaine shipment seizures that were in excess of 150kg during this time period had an average age of 18.2±1.4months, whereas smaller shipment seizures were significantly older with an average age of 22.3±0.6months. Analyses of the largest cocaine shipment seizures suggested that these seizures were composed of specimens with different ages, possibly representing accumulations over as much as a 31-month period.