Carfentanil (methyl 1-(2-phenylethyl)-4-[phenyl(propanoyl)amino]piperidine-4- carboxylate) is the most potent opioid used commercially with a quantitative potency approximately 10,000 times that of morphine and 100 times that of fentanyl. The drug is marketed under the trade name ‘Wildnil’ as a general anesthetic agent for large animals. Like its analogue fentanyl, Carfentanil is lipophilic and will readily and rapidly cross the blood/brain barrier.
In a recent paper published in Forensic Science International (DOI: https://doi.org/10.1016/j.forsciint.2020.110215) by Craig Chatterton et al., UCT’s famous Clean Screen® DAU cartridges (CSDAU203) were employed to extract Carfentanil from post mortem blood samples submitted to a regional medical examiner’s office in Canada.
For all calibrators, controls, and case-spike samples the precision ranged from 0.6% – 8.4% (n=108). The limit of detection was confirmed at 0.005 µg per L. Minimal Carfentanil carryover was observed (0.065%). Minimal ionization effects were observed as neat vs matrix reconstituted samples gave similar area responses; percent difference ranged from 5.3% to 15.6% (n=6). When the validated method was applied to 290 genuine post mortem blood samples, the authors found mean concentrations of Carfentanil were found to be 0.362 µg per L (femoral), 0.442 µg per L (iliac), 0.484 µg per L (cardiac) and 0.692 µg per L (subclavian).
With the advent of newer synthetic opioids such as Carfentanil, forensic toxicologists require solid phase extraction sorbents to efficiently extract them from challenging matrices such as postmortem blood. Click here for more information regarding Clean Screen solid phase sorbents.