title: Simultaneous determination of six urinary porphyrins using liquid chromatography-tandem mass spectrometry.
abstract: A liquid chromatographic-tandem mass spectrometric (LC-MS-MS) method without sample pretreatment was developed and validated for determination of porphyrins in samples of canine urine. Acidified urine samples were directly injected into the LC-MS system and a gradient elution program was applied. The mass spectrometer was operated in the multi-reaction monitoring (MRM) mode and six porphyrins were detected with excellent sensitivity and selectivity. The lower limits of quantification were 0.014 nmol/mL for mesoporphyrin IX, coproporphyrin I, 5-carboxylporphyrin, 6-carboxylporphyrin and 7-carboxylporphyrin, and 0.029 nmol/mL for uroporphyrin I. Good ln-quadratic responses of calibration standards over the range 0.01 to 1.0 nmol/mL for mesoporphyrin IX, coproporphyrin I, 5-carboxylporphyrin, 6-carboxylporphyrin and 7-carboxylporphyrin, and 0.02 to 1.0 nmol/mL for uroporphyrin I were demonstrated. This method should be easily adapted through cross-validation for use in determining the effects of chemicals and pharmaceuticals on the urinary excretion profile of porphyrins in preclinical studies with other species, and in assisting the diagnosis of porphyria in clinical studies.
authors.affiliation: WIL Research Laboratories, Inc., 44805, Ashland, OH, USA. wbu@wilresearch.com
authors.forename: Wei
authors.initials: W
authors.lastname: Bu
authors.forename: Nichole
authors.initials: N
authors.lastname: Myers
authors.forename: Jane D
authors.initials: JD
authors.lastname: McCarty
authors.forename: Tom
authors.initials: T
authors.lastname: O'Neill
authors.forename: Shelly
authors.initials: S
authors.lastname: Hollar
authors.forename: Philip L
authors.initials: PL
authors.lastname: Stetson
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Sved
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D011166:Porphyrins / Q000652:urine*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D011166:Porphyrins