During 2000-2001, the Government Laboratory of Hong Kong analyzed over 600,000 ecstasy tablets from more than 2,600 cases. Using GC-MS and FTIR, the tablets were categorized into four groups based on their major amphetamine-type stimulant: MDMA, methamphetamine, MDA, or amphetamine. MDMA tablets constituted 98% of all ecstasy tablets examined in 2000 and 71% in 2001. Chemical profiling of 613 MDMA cases (123,776 tablets) in 2001, using GC-MS and HPLC, allowed determination of whether tablets from different seizures shared a common origin. Common impurities detected included MDP2P, MDP, MDB, piperonal, and N-formyl-MDMA, which served as markers for inferring synthetic routes. The finding of a dihydrogen phosphate salt of MDMA (HMDMA)H2PO4 was noted, with a 1:1 ratio of phosphate to MDMA.
Since November 2018, the ketamine analog fluorodeschloroketamine (FDCK) has appeared in Hong Kong forensic cases. A retrospective study of drug seizures and driving-under-the-influence cases up to December 2019 found 74 drug seizure cases (151 items) and 6 drug driving cases. Most seized items contained only FDCK (about 67%) or a mixture with ketamine (about 28%), with purity similar to ketamine seizures. In drug driving cases, blood FDCK concentrations ranged from below 0.002 to 1.1 μg/mL, and other psychoactive substances were also present. The two cases with highest FDCK blood levels (1.1 and 0.87 μg/mL) may have contributed to impairment, though other drugs complicate interpretation.
A roadside testing protocol using field impairment tests (FIT) can detect ketamine-impaired drivers with over 90% accuracy when salivary ketamine concentrations exceed 300 ng/mL. Among 62 volunteers exiting discos in Hong Kong, 39 had ketamine in their oral fluid. Of 21 ketamine-only users, 71% were identified by FIT. Typical signs of ketamine impairment include lack of convergence, horizontal gaze nystagmus, elevated pulse rate, and poor performance on divided attention tests, particularly walk-and-turn and one-leg stand.