Detection of low levels of flunitrazepam and its metabolites in blood and bloodstains.

Detection of low levels of flunitrazepam and its metabolites was developed using solid-phase extraction to isolate the drugs from whole liquid blood and dried bloodstains, with subsequent derivatization with pentafluoropropionic anhydride (PFPA) followed by N-(tert-butyldimethyl-silyl)-N-methyl-trifluoroacetamide (MTBSTFA) with 1% TBDMSCI. Analysis was confirmed by gas chromatography/mass spectroscopy using select ion monitoring (sim) in electron impact mode. The limit of detection of this procedure using 1 ml of blood was determined to be 0.1 microgram/dl.