Wastewater-based monitoring of 2-fluoro-deschloroketamine abuse from 2019 to 2021 in a southern Chinese province

2-fluoro-deschloroketamine (FDCK) is a ketamine (KET) analog and new psychoactive substance that has appeared on the drug market in Europe and China in the past few years. The substance has been recently listed as a controlled drug by the narcotics control authority of China. In this work, FDCK and its metabolite nor-fluoro-deschloroketmaine (N-FDCK) in wastewater were analyzed for the first time to monitor FDCK abuse in a southern Chinese province that used to be a major producer and consumer of ketamine. For comparison, KET and its metabolite, nor-ketamine (N-KET) were monitored simultaneously. The concentration ratios between FDCK and N-FDCK were not statistically different from those of KET and N-KET. The average FDCK loads in the province in 2019 were higher than KET loads in most major cities in China in 2014 (when KET abuse hit its peak in the country). Rough estimation of FDCK and KET consumption revealed that FDCK was the predominant synthetic drug in the province in 2019, indicating rapid spread of the substance since its first appearance on the market. FDCK consumption decreased dramatically in 2020 and 2021, due to proactive actions by the local drug police before its listing as a controlled drug. Despite the dramatic decrease, FDCK was still the drug with greatest consumption by 2021, indicating that this substance persisted on the market even in the presence of forceful law enforcement. This finding also demonstrates that this substance may indeed have similar or even improved psychoactive effects relative to KET. Quick spread and persistence of FDCK demonstrated here indicates the urgent need to conduct wastewater-based monitoring of the abuse of the substance in other Chinese provinces and other countries. • FDCK abuse was examined in a southern Chinese province for three consecutive years. • Ketamine abuse was also examined in the province for comparison. • Quick spread and persistence of FDCK abuse was demonstrated.