OXY Analysis
Analysis of OXY was conducted using a validated reversed phase LC-MSMS
method. Reversed phase chromatography was performed using a Waters
XSelect CSH C18 column (2.1 x 50 mm, 2.5 µm particle size) and a 0.1%
formic acid / acetonitrile gradient at 0.5 mL/min flow rate. The
injection volume was 8 µL and the total run time was 6 minutes.
Quantitation was performed on a Shimadzu LCMS-8060 instrument in
positive ESI mode using multiple reaction monitoring (MRM).
Parent/daughter transitions acquired for quantitation were
1007.4>723.3 (single charge) and 504.3>285.2
(double charge). The validated range was 20 – 100 ng/mL OXY using
external standard quantitation. It should be noted that a LC-MSMS method
was used in preference to pharmacopoeial methods to provide the
necessary sensitivity to quantify the low concentrations of OXY present
when ampoules are further diluted in preparations for infusion use.