Detection and quantification of drugs on banknotes by LC-MS/MS with a fast and non-destructive sample preparation: a comparison of three cities.

Purpose: The analysis of drug residues on some currencies is well-established in the literature. However, there is no published study describing the presence of drug residues on Turkish paper currency.

Methods: This study focused on the analysis of 14 drug residues present on 600 Turkish banknotes collected from three different cities: Ankara, Adana, and Istanbul. The banknotes underwent preparation by a non-destructive and straightforward extraction method using methanol. To investigate the extent of contamination a method was subsequently developed and validated for liquid chromatography triple quadrupole mass spectrometry analysis to detect and quantify the target analytes. The investigated substances included benzoylecgonine, cocaine, heroin, codeine, morphine, 6-monoacetylmorphine (6-AM), amphetamine, methamphetamine, 3,4-methylenedioxy-N-methamphetamine (MDMA), methyl 3,3-dimethyl-2-(1-(pent-4-en-1-yl)-1H-indazole-3-carboxamido)butanoate (MDMB-4EN-PINACA), N-[1-(aminocarbonyl)-2,2-dimethylpropyl]-1-butyl-1H-indazole-3-carboxamide (ADB-BUTINACA), tetrahydrocannabinol (THC), pregabalin, ketamine, and tramadol.

Results: The calculated mean concentrations per note were 475.5 ng cocaine, 660.7 ng methamphetamine, 220.4 ng benzoylecgonine, 36.5 ng ketamine, 46.0 ng amphetamine, 120.6 ng 6-AM, 22.9 ng morphine, 6.3 ng codeine, 107.4 ng THC, 1.3 ng MDMB-4en-PINACA, 1.1 ng ADB-BUTINACA and 65.9 ng MDMA. Our findings indicate that banknotes commonly circulated in the three cities were primarily contaminated with methamphetamine and cocaine.

Conclusions: This study highlights the prevalence of drug residues on banknotes and raises concerns about their potential impact. The contamination of Turkish currency with drug residues is a strong indication of the widespread use of banknotes in drug trafficking.