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

## TL;DR

This study analyzed Turkish banknotes from three cities and found significant levels of drug residues, particularly methamphetamine and cocaine, suggesting their use in drug trafficking.

## Contribution

The study is the first to report drug residues on Turkish paper currency and compares contamination levels across three cities.

## Key findings

- Methamphetamine and cocaine were the most prevalent drug residues on Turkish banknotes.
- Banknotes from Ankara, Adana, and Istanbul showed widespread contamination with illicit drugs.
- Non-destructive extraction using methanol enabled efficient detection and quantification of drug residues.

## Abstract

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.

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.

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.

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.