Mepirapim hydrochloride, acetyl fentanyl, and acetyl fentanyl-d5 were purchased from Cayman Chemical (Ann Arbor, MI, USA). Other common chemicals used in this study were of the highest purity commercially available.
To prepare the calibrators and quality controls, we collected human whole blood and urine from two healthy volunteers with no known diseases and no history of drug use. Informed consent was obtained from both participants who supplied blood and urine for use as blank matrices. The samples obtained in December 2013 were stored at −80 °C until analysis.
To prepare the calibrators and quality controls, we collected human whole blood and urine from two healthy volunteers with no known diseases and no history of drug use. Informed consent was obtained from both participants who supplied blood and urine for use as blank matrices. The samples obtained in December 2013 were stored at −80 °C until analysis.