(+)-Norpropoxyphene-d5 (maleate) is an analytical reference standard intended for use as an internal standard for the quantification of norpropoxyphene by GC- or LC-MS. Norpropoxyphene is categorized as an opioid.1 It is a metabolite of propoxyphene .2 This product is intended for research and forensic applications.
1.Depriest, A., Heltsley, R., Black, D.L., et al.Urine drug testing of chronic pain patients. III. Normetabolites as biomarkers of synthetic opioid useJ. Anal. Toxicol.34(8)444-449(2010) 2.Crews, B.A., Mikel, C., Latyshev, S., et al.Unstable propoxyphene metabolite excreted in human urine is detected by liquid chromatography-tandem mass spectrometryJ. Anal. Toxicol.33(7)379-383(2009)