Discovery of syn-/anti-cocaine-N-oxide diastereomers in unwashed postmortem hair via LC-MS-MS.
The discovery of two cocaine-N-oxide (CNO) diastereomers, syn- and anti-CNO, is reported for the first time. Prior to this study, only one structural form of CNO was known to exist and has not been analyzed in hair before. CNO is a metabolite of cocaine (COC) and may be considered as an additional biomarker of COC use, along with other known COC metabolites. The analysis of COC in hair for forensic applications is under scrutiny due to the possibility of external contamination. A qualitative liquid chromatography-tandem mass spectrometry method was developed, validated and applied to unwashed postmortem hair samples from drug users. The limit of detection in hair was 8 pg/mg (using 10 mg of unwashed hair) for each CNO diastereomer. The presence of both syn- and anti-forms of CNO was verified in vivo using hair samples collected from known COC-using individuals. Due to the low levels of CNO, it will not always be detectable in COC user hair. In the hair samples analyzed, syn-CNO was detected in more samples than anti-CNO. The stereoselective N-oxidation of COC which favors syn-CNO could have a diagnostic value for COC ingestion determination in hair analysis.
Counterterrorism and Forensic Science Research Unit, Visiting Scientist Program, Federal Bureau of Investigation Laboratory Division, Quantico, VA 22135, USA.
Christine M
CM
Marsh
Counterterrorism and Forensic Science Research Unit, Visiting Scientist Program, Federal Bureau of Investigation Laboratory Division, Quantico, VA 22135, USA.
Lindsey R
LR
Crawley
Counterterrorism and Forensic Science Research Unit, Visiting Scientist Program, Federal Bureau of Investigation Laboratory Division, Quantico, VA 22135, USA.
Sarah K
SK
Himes
Counterterrorism and Forensic Science Research Unit, Visiting Scientist Program, Federal Bureau of Investigation Laboratory Division, Quantico, VA 22135, USA.
Roman
R
Aranda
Counterterrorism and Forensic Science Research Unit, Federal Bureau of Investigation Laboratory Division, 2501 Investigation Parkway, Quantico, VA 22135, USA mark.l.miller@ic.fbi.gov.
Mark L
ML
Miller
D002853:Chromatography, Liquid; D003042:Cocaine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D006197:Hair / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D013287:Illicit Drugs / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D057230:Limit of Detection; D011180:Postmortem Changes; D015203:Reproducibility of Results; D013048:Specimen Handling; D013237:Stereoisomerism; D015813:Substance Abuse Detection / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry
D013287:Illicit Drugs; C486959:cocaine N-oxide; D006861:Hydrogen Peroxide; D003042:Cocaine