Benzoylecgonine

Benzoylecgonine is the major metabolite of cocaine. It is formed by hydrolysis of cocaine in the liver, catalysed by carboxylesterases. It is excreted in the urine of cocaine users after processing in the liver.

In 2005, scientists found surprisingly large quantities of benzoylecgonine in Italy's Po River and used its concentration to estimate the number of cocaine users in the region. In 2006, a similar study was performed in the Swiss ski town of Saint-Moritz using waste water to estimate the daily cocaine consumption of the population.