Rapid Quantification of Urinary Oxycodone and Oxymorphone Using Fast Gas Chromatography-Mass Spectrometry

Abstract

Human urine specimens that were determined to be presumptively positive for oxycodone and its metabolite, oxymorphone, by immunoassay screening were assayed using fast gas chromatography-mass spectrometry to positively identify and quantify the oxycodone and oxymorphone present. Urine specimens were first spiked with deuterated internal standards, oxycodone-d(3) and oxymorphone-d(3), subjected to acid hydrolysis, and then extracted using a positive-pressure manifold and mixed-bed solid-phase cartridge extraction methodology. Extracts were derivatized using methoxylamine and acetic anhydride. The acetylated-oxime derivatives of oxycodone and oxymorphone were identified and quantified using a selective ion monitoring (SIM). The method was found to be linear for both analytes to 1600 ng/mL, and limits of detection for oxycodone and oxymorphone were found to be 40 ng/mL and 20 ng/mL, respectively. Interlaboratory data comparisons (n = 40) showed correlation coefficients of 0.9999 and 0.9997 for oxycodone and oxymorphone, respectively. Twelve semisynthetic, structurally similar compounds at concentrations of 5000 ng/mL were assayed in the presence of oxycodone and oxymorphone and found not to interfere with identification and quantitation by this method. Finally, exact mass and tandem mass spectrometry techniques were employed to elucidate the structures of the SIM ions.

Rapid GC–MS confirmation of amphetamines in urine by extractive acylation

“…Rapid chromatographic separation with microbore capillary columns [26] and quick temperature gradients [16,27] in fast GC-MS analysis have indicated the possibility of accurate quantitation in relatively short analysis times with adequate resolution between structurally close-related components. Care must, however, be taken in addressing the number of data points that define a chromatographic peak for forensic confirmations in such methodologies [28][29][30].…”

Re: Pergolizzi et al., 2010: The Role of Urine Drug Testing for Patients on Opioid Therapy

“…As Table 1 was unreferenced, we could not ascertain the veracity of its contents without a full literature search, which we discuss below. First, the table shows inconsistency because it states that oxymorphone is detectable as a metabolite of oxycodone (which we agree with 2 and the literature supports 3–6 ), but subsequently suggests that oxymorphone is not detectable because there is not an “assay commercially available at this time.” This statement is inaccurate as there is substantial literature supporting that oxymorphone can be detected in the urine. Even as far back as 1995, a variety of chromatographic/mass spectrometry methods could detect oxymorphone 7 .…”

“…Even as far back as 1995, a variety of chromatographic/mass spectrometry methods could detect oxymorphone 7 . Today, research and commercial laboratories test urine for oxymorphone using several different liquid/gas chromatographic and mass spectrographic methods 3,4,6,8,9 . However, it is often preferable to use immunoassays for screening before confirmation because of their ease and efficiency at streamlining laboratory workload 4 .…”

High Performance Liquid Chromatographic Method for Simultaneous Quantification of Naloxone and Oxycodone

“…Naloxone has been determined by spectrophotometry [9], HPLC [9][10][11][12] and LC-MS [13,14] methods. HPLC [15], HPTLC [16], LC-MS [17][18][19], GC-MS [20,21] and capillary electrophoresis [22] methods have been adapted to the determination of oxycodone in biological samples like human blood, plasma, urine and in oral pharmaceutical solutions. Therefore, the present study was aimed to develop and validate a HPLC assay method for simultaneous quantification of naloxone and oxycodone in bulk and combined tablet dosage…”