Analysis of Opioids in Urine Specimens by Solid Phase Extraction (SPE) and Ultra Performance Liquid Chromatography/Tandem Mass Spectrometry (UPLC/MS/MS)

Johnson, Melissa A., Whitehall PA; Williams, Chinyere M., Nottingham UNITED KINGDOM; Hackett, Jeffery, Liverpool UNITED KINGDOM; Lemos, Nikolas P., San Francisco CA