[CAS Number 118357-29-2] Fentanyl-D5 is an internal standard used for the quantification of fentanyl. Fentanyl is a synthetic opioid agonist possessing anesthetic and analgesic properties. Eighty to one hundred times more potent than morphine, Fentanyl is a highly addictive and commonly abused narcotic. Fentanyl-D5 is available as reference material (bulk powder and/or solution) and as calibrated, Ready-to-Use, certified reference material (CRM). This product is designed for qualitative and quantitative protocols and can be used for forensic, toxicology, research, and other chemical/biochemical analytical applications.