Quantitative measurement of acetyl fentanyl and acetyl norfentanyl in human urine by LC-MS/MS.
Patton AL, Seely KA, Pulla S, Rusch NJ, Moran CL, Fantegrossi WE, Knight LD, Marraffa JM, Kennedy PD, James LP, Endres GW, Moran JH. Quantitative measurement of acetyl fentanyl and acetyl norfentanyl in human urine by LC-MS/MS. Anal Chem. 2014 Feb 04; 86(3):1760-6.