In spring 2013, a cluster of drug overdose deaths baffled Rhode Island toxicologists for weeks. They finally identified the culprit, a synthetic drug called acetyl fentanyl. Currently, there are no validated methods for measuring this compound in human samples, and standard forensic drug tests provide conflicting results. Now, a team has designed a new toxicology test that can detect low concentrations of acetyl fentanyl (Anal. Chem. 2013, DOI: 10.1021/ac4036197).
Acetyl fentanyl is an analog of the opioid fentanyl, a potent prescription painkiller. Sixty-four deaths in Rhode Island and Pennsylvania have now been linked to the substance. The Centers for Disease Control and the Drug Enforcement Administration have since issued alerts on acetyl fentanyl, which has never been approved for human use and is regulated as a controlled substance analog.
Jeffery H. Moran of the University of Arkansas for Medical Sciences and his colleagues wanted a procedure that would allow them to identify and measure acetyl fentanyl and its predicted metabolite, acetyl norfentanyl, in urine. First, researchers from Cayman Chemical on Moran’s team synthesized the two compounds for use in testing. Then, drawing on studies of fentanyl, Moran’s team spiked samples of human urine with the synthesized compounds. Next the researchers ran the samples through a cation exchange cartridge to remove most of the other components of urine. This step allowed for the separation and detection of ultralow levels of the target compounds by liquid chromatography and tandem mass spectrometry.
Their method could detect as little as 1 ng of acetyl fentanyl per mL—a concentration one twenty-thousandth of what might be expected in a urine sample from an overdose victim. The detection method showed high accuracy and precision, and could be reproduced at most toxicology labs, Moran says.