title: Galactonate determination in urine by stable isotope dilution gas chromatography-mass spectrometry.
abstract: A stable isotope dilution assay was developed for the sensitive determination of D-galactonic acid. D-[U-13C(6)]galactono-1,4-lactone was prepared as internal standard. Unlabelled and U-13C-labelled D-galactonic acid species were converted to the N-(1-butyl)galactonamide pentaacetate derivatives and assessed by gas chromatography-mass spectrometry (GC-MS). Positive chemical ionisation and monitoring of the [MH-60](+)-ions in the galactonate chromatographic peak at m/z 402 and m/z 408 were used for quantification. The procedure was applied to study the variability of D-galactonate excretion in healthy subjects and galactosemic patients and to monitor the D-galactonate-D-galactitol ratio in human urine.
authors.affiliation: Klinik für Allgemeine Pädiatrie, Universitätsklinikum, Heinrich-Heine-Universität Düsseldorf, Metabolic Unit, Moorenstrasse 5, D-40225 Düsseldorf, Germany. schadewa@uni-duesseldorf.de
authors.forename: Peter
authors.initials: P
authors.lastname: Schadewaldt
authors.forename: Hans-Werner
authors.initials: HW
authors.lastname: Hammen
authors.forename: Sara
authors.initials: S
authors.lastname: Stolpmann
authors.forename: Loganathan
authors.initials: L
authors.lastname: Kamalanathan
authors.forename: Udo
authors.initials: U
authors.lastname: Wendel
mesh_terms: D000293:Adolescent; D000328:Adult; D002247:Carbon Isotopes; D002648:Child; D002675:Child, Preschool; D005260:Female; D004376:Galactitol / Q000652:urine; D005690:Galactose / Q000652:urine; D005693:Galactosemias / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007201:Indicator Dilution Techniques; D007783:Lactones / Q000652:urine; D008297:Male; D011786:Quality Control; D012680:Sensitivity and Specificity; D013400:Sugar Acids / Q000652:urine*
chemical_list: D002247:Carbon Isotopes; D007783:Lactones; D013400:Sugar Acids; D004376:Galactitol; C012991:galactonic acid; D005690:Galactose