Analysis of 4-fluoroamphetamine in cerumen after controlled oral application

Cerumen was found to be a promising alternative specimen for the detection of drugs. In a pilot study, drugs of abuse were identified at a higher detection rate and a longer detection window in cerumen than in urine. In this study, cerumen from subjects was analyzed after they ingested the designer stimulant 4-fluoroamphetamine (4-FA) in a controlled manner.

METHODS: Twelve subjects ingested placebo and 100 mg of 4-FA. Five of them were also given 150 mg of 4-FA in 150 mL Royal Club bitter lemon drink at least after 7 days. Cerumen was sampled using cotton swabs at baseline, 1 h after the ingestion of the drug and at the end of the study day (12 h). After extraction with ethyl acetate followed by solid-phase extraction, the extracts were analyzed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS).

RESULTS AND DISCUSSION: In the cerumen of all 12 subjects, 4-FA was detected 12 h after its ingestion; in most subjects, cerumen was detected after 1 h of ingestion, ranging from 0.06 to 13.90 (median 1.52) ng per swab. The detection of 4-FA in cerumen sampled 7 days or more after the first dose suggested a long detection window of cerumen.

CONCLUSIONS: Cerumen can be successfully used to detect a single drug ingestion even immediately after the ingestion when a sufficient amount of cerumen is used.