title: Simultaneous quantitation of opioids in blood by GC-EI-MS analysis following deproteination, detautomerization of keto analytes, solid-phase extraction, and trimethylsilyl derivatization.
abstract: Seven opioid analytes including codeine, morphine, 6-acetylmorphine, hydrocodone, hydromorphone, oxycodone, and oxymorphone were detected in postmortem blood (n > 1000). Two milliliters of specimen was deproteinated with approximately 2.5 mL of methanol and derivatized with hydroxylamine before solid-phase extraction and derivatization with BSTFA + 1% TMCS. Extracts were assayed by gas chromatography-electron impact-mass spectrometry utilizing selected ion mode. One-microliter aliquots were injected onto an HP-1MS capillary column (30 m x 0.25-mm i.d., 0.25 microm) with a helium linear velocity of 62 cm/s. Temperature programming began at 160 degrees C (hold 0 min), then increased at rates of 35 degrees C/min to 195 degrees C, 5 degrees C/min to 240 degrees C, and 30 degrees C/min to 300 degrees C (hold 2 min) resulting in a total run time of 14-min. Quantitative determinations were based on the ratios of the analyte peak areas to the corresponding deuterated analogues. Calibration curves were linear for the following concentrations: 10-500 ng/mL (6-AM), 100-2000 ng/mL (oxycodone), and 50-1000 ng/mL (all other opioids). LOQs ranged from 5 ng/mL (6-AM) to 20 ng/mL (oxycodone). Between-run precision yielded CVs ranging from 2.79% to 5.34% (n = 12). These data suggest that methanolic deproteination and dual derivatization improve separation and simultaneous quantitation of seven opioid analytes in difficult matrices.
authors.affiliation: Office of the Chief Medical Examiner, Chapel Hill, North Carolina 27599, USA. jmiller@ocme.unc.edu
authors.forename: Jeri D
authors.initials: JD
authors.lastname: Ropero-Miller
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Lambing
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Winecker
mesh_terms: D005554:Forensic Medicine / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry; D007536:Isomerism; D009022:Morphine Derivatives / Q000097:blood*; D009294:Narcotics / Q000097:blood*; D011506:Proteins / Q000737:chemistry*; D015813:Substance Abuse Detection / Q000379:methods*; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
chemical_list: D007202:Indicators and Reagents; D009022:Morphine Derivatives; D009294:Narcotics; D011506:Proteins; D014297:Trimethylsilyl Compounds; C047270:N,N-bis(trimethylsilyl)-2,2,2-trifluoroacetamide