title: Porphyrin profiles in blood, urine and faeces by HPLC/electrospray ionization tandem mass spectrometry.
abstract: A high-resolution high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry method is described for the analysis of porphyrins in blood, urine and faeces. The gradient elution reversed-phase HPLC system using acetonitrile-methanol-1 m ammonium acetate/acetic acid buffer (pH 5.16) as gradient solvent mixtures was able to separate all porphyrin metabolites, including the type I and type III isomers of uroporphyrin, hepta-, hexa- and penta-carboxylic acid porphyrins and coproporphyrin. The porphyrins were positively identified by the protonated molecules [M+H](+) and further characterized by tandem mass spectrometric analysis with each porphyrin giving a characteristic collisioninduced dissociation product ion spectrum. The mass chromatograms obtained by HPLC/ESI MS are useful for the differential diagnosis of the porphyrias, since each type of porphyria has a typical porphyrin excretion pattern.
authors.affiliation: MRC Bioanalytical Science Group, School of Biological and Chemical Sciences, Birkbeck, University of London, UK.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Danton
authors.forename: Chang Kee
authors.initials: CK
authors.lastname: Lim
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005243:Feces / Q000737:chemistry*; D011166:Porphyrins / Q000032:analysis* / Q000097:blood / Q000652:urine; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D011166:Porphyrins