Rapid method for the solid-phase extraction and GC-MS analysis of flunitrazepam and its major metabolites in urine

Recently, flunitrazepam (Rohypnol) has become an increasingly popular drug of abuse among young adults, who take it for its euphoric effects. In other cases, the drug has been used by rapists for its sedative and hypnotic effects that can induce a catatonialike trance and memory loss in potential victims; as a result, it has been nicknamed the "date-rape drug". For these reasons, the Drug Enforcement Administration recently considered adding the drug (a.k.a. "Roofies") to the same category as heroin and LSD. A selective and sensitive technique has been developed for extracting, detecting, and identifying flunitrazepam and its two major metabolites (7-aminoflunitrazepam and N-desmethylflunitrazepam) in human urine. Using a solid-phase extraction cartridge containing a "mixed-mode" bonded silica gel (Bond Elut Certify), flunitrazepam and its metabolites were selectively isolated from other urine components and quantitated and identified by gas chromatography-tandem mass spectrometry with a benchtop ion mass spectrometer. The extraction method is rapid, reproducible, and precise, and it has a broad linear working range. The overall extraction efficiency was found to be more than 90% for the parent drug as well as the two major metabolites.