Surface swabbing of nightclub venues to monitor the presence of cocaine, ketamine, and MDMA

Background: The drug landscape in the US is rapidly shifting, and alternate methods of drug surveillance that do not involve human subjects may help overcome limitations of current methods. In this study, we focus on nightclubs, where use of cocaine, ketamine, and 3,4-methylenedioxymethamphetamine (MDMA) is prevalent.Objectives: In this proof-of-concept study, we assessed the feasibility of surface swabbing in nightclub venues in New York City as an environmental method for monitoring the presence of commonly used party drugs, and we compared findings from swabs collected from non-nightclub public settings.Methods: Swabbing was conducted inside 9 nightclub venues on 15 nights in 2025, yielding 46 separate surface samples. For comparison, 16 additional swabs were collected from non-nightclub public environments we considered “controls.” Samples were analyzed via liquid chromatography quadrupole time-of-flight mass spectrometry (LC–QTOF–MS).Results: Cocaine and ketamine were detected at every nightclub on every night. Across all nightclub swabs, cocaine was most often detected (83%), followed by ketamine (78%), and MDMA (26%). We also detected lidocaine (11%), levamisole (4%), phenacetin (4%), 2-methylmethcathinone (4%), 4-methylmethcathinone (4%), bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (BTMPS; 4%), and quinine (4%). Detection of cocaine, ketamine, and MDMA was relatively consistent within the same night, and detection was also consistent by venue across nights with some variation in number of swabs testing positive. Among non-nightclub comparison swabs, cocaine and ketamine were detected on 44% and 13% of surfaces, respectively.Conclusions: This study demonstrated that surface swabbing can possibly serve as a useful method for drug monitoring at such venues.