title: [Direct spectrophotometric determination of urinary uroporphyrin and coproporphyrin using zerocrossing second derivative spectrophotometry].
abstract: The use of zero-crossing second-derivative spectrophotometry allows simultaneous determination of uroporphyrin and coproporphyrin directly in urines. Linearity and repeatability are excellent. Detection limit is about 8 nmol/l. Specificity is excellent too, except in unusual porphyrias where porphyrins with 5, 6 or 7 carboxylic groups are encountered. In such a case, this method allows the detection of increased porphyrins contents. The main advantage of this technique is its simplicity: it needs just to acidify urines and to plot a spectrum from 380 to 440 nm to determine the uroporphyrin and coproporphyrin concentrations. So it may be a very useful technic for clinical biochemistry laboratories in charge of monitoring patients suffering from porphyria.
authors.affiliation: Laboratoire Central de Biochimie, Centre Hospitalier de Bicêtre, Le Kremlin-Bicêtre.
authors.forename: H
authors.initials: H
authors.lastname: Ficheux
authors.forename: P
authors.initials: P
authors.lastname: Levillain
authors.forename: A
authors.initials: A
authors.lastname: Lemonnier
mesh_terms: D003306:Coproporphyrins / Q000652:urine*; D011165:Porphyrinogens / Q000652:urine; D011166:Porphyrins / Q000652:urine*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014578:Uroporphyrins / Q000652:urine*
chemical_list: D003306:Coproporphyrins; D011165:Porphyrinogens; D011166:Porphyrins; D014578:Uroporphyrins
vernacular_title: Dosage spectrophotométrique direct de l'uroporphyrine et de la coproporphyrine urinaires par la méthode du point d'annulation en dérivée seconde.