Nandrolone criteria for 19-norandrosterone Isotope Ratio Mass Spectrometric confirmation

The detection of the use of nandrolone and other 19-norsteroids is based primarily upon the identification of the main urinary metabolite, 19-norandrosterone (19-NA) in a concentration (derived from hydrolysis with β-glucuronidase) greater than the Decision Limit (DL), as established in the DL Technical Document. The presence of 19-NA in urine samples can be originated by in-vivo endogenous production (ovulation or pregnancy in females) and/or exogenous administrations (nandrolone or nandrolone precursors) or by ex-vivo production in urine by in-situ 19-demethylation of androsterone (A) (active urines).