title: On-line LC-MS analysis of urinary porphyrins.
abstract: A reversed-phase high-performance liquid chromatography-mass spectrometry (LC-MS) method is described for the separation and simultaneous analysis of porphyrins related to disorders of heme biosynthesis (uro-, heptacarboxylic, hexacarboxylic, pentacarboxylic, and coproporphyrins). The method involves initial porphyrin esterification and extraction from urine. Detection and quantification is performed from the extracts by separation with a Hypersil BDS column and on-line detection by MS through coupling with an atmospheric pressure chemical ionization interface. The porphyrin esters are detected as protonated molecules [M + H]+. Their mass spectra also exhibit an [M + Na]+ fragment of lower intensity. The analytical performance of this method is compared with those of LC with UV and fluorescence detection. LC-MS used in selective [M + H]+ ion monitoring provides the lowest detection and quantitation limits. In scan mode, this LC-MS method affords, without further isolation or concentration steps, the measurement of mass spectra of unknown compounds present in the urine of patients with altered porphyrin excretion.
authors.affiliation: Department of Environmental Chemistry (ICER, CSIC), Barcelona, Catalonia, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Ausió
authors.forename: J O
authors.initials: JO
authors.lastname: Grimalt
authors.forename: D
authors.initials: D
authors.lastname: Ozalla
authors.forename: C
authors.initials: C
authors.lastname: Herrero
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D011166:Porphyrins / Q000652:urine*; D015203:Reproducibility of Results
chemical_list: D011166:Porphyrins