The Synthetic Drug 3-Methylfentanyl: Identification and Quantitation of Powdered Samples

Paraphernalia, residue in plastic bag corners, and powdered street samples analyzed by gas chromatography/mass spectrometry (GC/MS) revealed the presence of cis and trans isomers of 3-methylfentanyl (3-MF). The isomers were differentiated by their retention times and by the smaller abundance ratios of ions at m/z 160 and 203 to the base ion of 259 for the more stable trans isomer. Quantitation of powdered samples was accomplished using a gas chromatograph/mass spectrometer with a HP5 column (25 m by 0.20 mm) and ketamine as an internal standard. Two cut street samples revealed higher percentages of the more potent cis isomer (0.26 and 0.37%) than the trans isomer (0.15 and 0.16%). With an average purity of 0.47% (4.7 µg/mg), about 100 µg of 3-MF would be present in a typical 20-mg packet, in comparison with 2000 µg of heroin with an average street composition of 10%. Since the potency of 3-MF is about 1000 times that of heroin, the 3-MF samples should have been diluted another 50-fold to contain about 0.1 µg/mg. The difficulty of cutting and inexperience with 3-MF contributed to the rash of overdoses in our area.