Description General description A stable-labled internal standard suitable for quantitation of nortetrazepam levels in urine, serum, or plasma by LC/MS or GC/MS for urine drug testing, clinical toxicology, forensic analysis, or isotope dilution methods. Nortetrazepam is a benzodiazepine derivative and one of the major metabolites of tetrazepam. Legal Information CERILLIANT is a registered trademark of Cerilliant Corporation