Determination of urinary deanol-N-oxide excretion profiles after ingestion of nutritional supplements containing deanol

2-(Dimethylamino)ethan-1-ol (Deanol) is a widely produced chemical used by both industry and consumers in a variety of applications. Meclofenoxate, a stimulant classified on the World Anti-Doping Agency Prohibited List, metabolizes into deanol and, presumably, its main metabolite deanol-N-oxide. Hence, using liquid chromatography-tandem mass spectrometry, a quantitative detection method for deanol-N-oxide in urine was developed. Subsequently, the urinary excretion of deanol-N-oxide after oral application of 130 mg of deanol was determined in six volunteers, and urine samples of a cohort of 180 male and female athletes from different sports were analyzed. In addition, urinary deanol-N-oxide was determined in an exploratory study with one volunteer ingesting 250 mg of meclofenoxate. The developed test method allowed for limits of detection and quantification for deanol-N-oxide at 0.05 and 0.15 μg/mL, respectively. Urinary deanol-N-oxide c_max levels were found between 100 and 250 μg/mL 2-5 h post-administration of 130 mg of deanol. Similarly, urine samples collected after the administration of 250 mg of meclofenoxate exhibited c_max levels of 115 μg/mL. In contrast, deanol-N-oxide urine concentrations of pre-administration specimens and 180 routine doping control urine sample were between 0.3 and 1.3 μg/mL and below limit of quantification and 1.8 μg/mL, respectively. The study suggests that the use of deanol and meclofenoxate results in significantly elevated urinary deanol-N-oxide levels. Whether or not monitoring deanol-N-oxide in doping controls can support decision-making processes concerning the detection of meclofenoxate use necessitates further investigations taking into consideration the elimination kinetics of 4-chlorophenoxyacetic acid, the main metabolite of meclofenoxate, and deanol-N-oxide.