Occurrence and sources of residues of drugs of abuse in an urban aquifer: Chemical analysis and solute transport modelling

This study investigated the occurrence and potential sources of residues of drugs of abuse in an urban aquifer beneath the City of Ljubljana using water analysis and a solute transport model designed to predict nitrogen distribution. Samples were collected from three sources: 28 wastewater samples (24-h composites), 4 aquifer-recharging river samples (grab), and 22 groundwater samples. The samples were analysed for residues of commonly (ab)used licit drugs (nicotine and alcohol), medications of abuse (morphine, methadone, codeine, and ketamine), and illicit drugs (tetrahydrocannabinol – THC, cocaine, amphetamines, and heroin) using liquid-liquid (alcohol residue) and solid-phase extraction, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Additionally, we used solute transport modelling to predict the spatial distribution of drug residues in the aquifer and their potential sources. Nicotine (up to 45,7 ng/L), cotinine (up to 5.86 ng/L), trans-3′-hydroxycotinine (up to 0.528 ng/L) and benzoylecgonine (up to 0.572 ng/L) were the most commonly detected drug residues in groundwater, followed by cocaine (更多