Impact of coca leaf flour candy consumption on cocaine and benzoylecgonine levels: The role of hygrine and cuscohygrine in distinguishing licit from illicit cocaine use

Abstract

The consumption of coca leaf products, a traditional practice in several Latin American countries, raises forensic challenges in distinguishing legal consumption from illicit cocaine use. This study investigates the implications of consuming coca flour-based candies on drug detection thresholds in oral fluid (OF) and urine for drug-impaired driving (DUID) and workplace drug testing (WDT) contexts. Three commercial candy brands were analyzed, revealing significant variability in coca alkaloid content. Volunteers consumed these candies under controlled conditions, with biological samples collected at various intervals. Key analytes, including cocaine (COC), benzoylecgonine (BE), ecgonine methyl ester (EME), tropococaine (TRO) and cocaethylene (CE), were quantified alongside coca leaf-specific markers (cuscohygrine, cinnamoylcocaine, and hygrine). Analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with multiple reaction monitoring mode (MRM) transitions to ensure specificity.