Screening for illicit drugs on Euro banknotes by LC–MS/MS

A method for the simultaneous quantification of illicit drugs on Euro banknotes, using an ultra-performance liquid chromatography tandem mass spectrometry, was developed and validated. The method included cocaine, benzoylecgonine, MDMA, MDEA, MDA, methamphetamine, diacetylmorphine, 6-MAM, morphine and Δ9-THC. Drug residues were monitored and quantified via positive ESI mode using multiple reaction monitoring. Banknotes were extracted with methanol by vigorous shaking. Recovery rates were in the range of 60–80%. Calibration was performed with spiked banknotes in the range of 10–100 ng/note (R2 0.98–0.99). Intra-day analysis showed fair precision and accuracy (≤15%). Matrix effects were in the range from 27% to 235%. 7–15 samples of each denomination were analyzed. The calculated median values per note were 106 ng cocaine, 43 ng benzoylecgonine, 41 ng heroin, 15.5 ng 6-MAM, 16.5 ng morphine, 9 ng MDMA and 7 ng methamphetamine. Δ9-THC was detected on 4 banknotes. MDEA and MDA were not detected on any note. A widespread background contamination for cocaine and opiates was demonstrated.