Presence of the ketamine analog of 2‐fluorodeschloroketamine residues in wastewater

Abstract

Ketamine (KET) analogs are increasingly emerging as new psychoactive substances (NPS). The present report describes the first detection of the KET analog, 2‐fluorodeschloroketamine (2F‐DCK), in influent samples collected from nine wastewater treatment plants in seven major Chinese cities from 2018 to 2020 by wastewater‐based epidemiology (WBE). An analytical method based on solid‐phase extraction and subsequent gas chromatography–mass spectrometry was developed for the detection of 2F‐DCK and KET. The stability experiments showed that 2F‐DCK and KET remained stable in wastewater for 15 days at room and frozen temperatures, and at two pH values (pH = 7 and pH = 2), with residue amounts between 90% and 110%. KET was detected in all samples, whereas 2F‐DCK was detected in only four samples: from Guangzhou in 2018, Shenzhen in 2019, and Quanzhou and Nanning in 2020, indicating that 2F‐DCK has been used as early as 2018 in China. The renal clearance of 2F‐DCK was predicted based on the quantitative structure–pharmacokinetic relationship model, which was used to calculate an excretion factor of 3.7. The 2F‐DCK consumption in four cities ranged from 3.71 ± 0.05 to 55 ± 0.09 mg/day/1000 inh, and KET ranged from 1.3 ± 0.04 to 76.5 ± 4.63 mg/day/1000 inh. This is the first study to investigate 2F‐DCK by WBE, which provides relevant real‐time data on the growth of NPS use, as well as useful information for the government to develop new policies.

2‐Fluorodeschloroketamine has similar abuse potential as ketamine

“…In China, the number of ketamine abusers is only less than that of methamphetamine and heroin 28 . In recent years, the abuse of 2‐FDCK as a ketamine substitute is on the rise in several countries, including China 3,12,16,19–21 . According to abusers of 2‐FDCK, 2‐FDCK has a potency comparable with ketamine 11 .…”

“…cyclohexan-1-one, 2-FDCK] is an emerging drug of abuse, 3 which has close structural homology with arylcyclohexylamine backbone of ketamine (Figure 1). 4,5 The synthesis of 2-FDCK was first reported in 1987.…”

“…28 In recent years, the abuse of 2-FDCK as a ketamine substitute is on the rise in several countries, including China. 3,12,16,[19][20][21] According to abusers of 2-FDCK, 2-FDCK has a potency comparable with ketamine. 11 However, there is relatively little knowledge about the abuse potential of 2-FDCK.…”

“…The numbers of new psychoactive substances (NPS) are continuously increasing, which includes a growing class of ketamine analogues 1,2 . 2‐Fluorodeschloroketamine [2‐(2‐fluorophenyl)‐2‐(methylamino) cyclohexan‐1‐one, 2‐FDCK] is an emerging drug of abuse, 3 which has close structural homology with arylcyclohexylamine backbone of ketamine (Figure 1). 4,5 The synthesis of 2‐FDCK was first reported in 1987 6 .…”

“…2‐FDCK was detected in whole blood and hair samples in Denmark in 2018 and 2019 18 . In China, 2‐FDCK was also detected in drug screening of urine samples, wastewater samples and seizures 3,12,19–21 . 2‐FDCK was legally regulated in China, Latvia, Belgium, Japan, Singapore, Sweden, Switzerland, Canada and the United Kingdom 22,23 but was not in many other countries.…”