Abstract:
A sensitive method for the determination of oxycodone
concentrations in plasma by high-performance liquid
chromatography (HPLC)–electrospray ionization–triple quadrupole
mass spectrometry is described. The method is rugged, reliable,
selective, and rapid with a run time of 2 min. One milliliter of
plasma is made basic and extracted with 2-mL duplicate portions
of 2% isoamyl alcohol in n-butyl chloride. The combined extracts
are then evaporated to dryness, reconstituted in 100 μL of the
mobile phase (15% methanol–85% water containing 0.1%
acetic acid), and injected onto the HPLC. The limit of quantitation
is 1 ng/mL, and the estimated limit of detection is 33 pg/mL
(signal-to-noise = 3). Standard curves are linear over the range
of 1 to 100 ng/mL with all correlation coefficient values greater
than 0.9989. The method is used to determine the concentration
of oxycodone in human plasma following the intravenous infusion
of doses ranging from 5 to 15 mg in which the analysis of over
3000 plasma samples is required.
