Directly coupled liquid chromatography with inductively coupled plasma mass spectrometry and orthogonal acceleration time-of-flight mass spectrometry for the identification of drug metabolites in urine: application to diclofenac using chlorine and sulfur detection.
We report the application of high-performance liquid chromatography (HPLC) linked to inductively coupled plasma mass spectrometry (ICPMS) and orthogonal acceleration time-of-flight mass spectrometry (oa-TOFMS) for the identification of phase I and II urinary metabolites of diclofenac. The metabolites were separated by reversed-phase HPLC monitored with a UV diode array detector (UV-DAD) after which 90% of the eluent was directed to an ICPMS source, with the remainder going to an oa-TOF mass spectrometer. Compounds containing (35)Cl, (37)Cl and (32)S were detected specifically using ICPMS and identified by oa-TOFMS. The metabolites detected and identified in this way included glucuronic acid and sulfate conjugates, mono- and dihydroxylated and free diclofenac. In addition a previously unreported in vivo metabolite, an N-acetylcysteinyl conjugate of diclofenac, was also characterised. This is the first application of the combination of HPLC/UV-DAD/ICPMS/oa-TOFMS for the investigation of the metabolic fate of chlorinated xenobiotics by direct biofluid analysis.
Corcoran
O
O
Biological Chemistry, Imperial College of Science, Technology and Medicine, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK.
Nicholson
J K
JK
Lenz
E M
EM
Abou-Shakra
F
F
Castro-Perez
J
J
Sage
A B
AB
Wilson
I D
ID
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism / Q000652:urine; D002713:Chlorine / Q000378:metabolism* / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D004008:Diclofenac / Q000378:metabolism* / Q000493:pharmacokinetics / Q000652:urine*; D005965:Glucuronates / Q000378:metabolism / Q000652:urine; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D015394:Molecular Structure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013056:Spectrophotometry, Ultraviolet; D013455:Sulfur / Q000378:metabolism* / Q000652:urine; D015262:Xenobiotics / Q000378:metabolism / Q000493:pharmacokinetics / Q000652:urine
D000894:Anti-Inflammatory Agents, Non-Steroidal; D005965:Glucuronates; D015262:Xenobiotics; D004008:Diclofenac; D002713:Chlorine; D013455:Sulfur