title: Tandem mass spectrometric assay of succinylacetone in urine for the diagnosis of hepatorenal tyrosinemia.
abstract: We describe an isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of succinylacetone (SA) in urine for the diagnosis of hepatorenal tyrosinemia (HT1). The method used 15N-labeled 5(3)-methyl-3(5)-isoxazole propionic acid as internal standard. Urine samples were oximated with hydroxylamine hydrochloride at 80 degrees C, extracted by solvent-solvent extraction, and followed by derivatization of the butyl ester. The butylated isoxazole derivatives of SA and its internal standard were detected and quantified using positive ion electrospray LC-MS/MS with selected reaction monitoring. The turnaround time between injections was 10 min. Calibration curves were linear over the range of 0.0633-63.3 micromol/L. The intra- and interday assay variations were less than 7%. Mean recoveries of SA at three different concentrations ranged from 96 to 109%. During the course of this study, we identified 12 new patients with HT1 and applied this method to follow up the treatment of 4 of these patients as well as previously diagnosed HT1 patients.
authors.affiliation: Department of Genetics, King Faisal Specialist Hospital and Research Center, P.O. Box 3354, Riyadh 11211, Saudi Arabia. rashed@kfshrc.edu.sa
authors.forename: Mohamed S
authors.initials: MS
authors.lastname: Rashed
authors.forename: Lujane Y
authors.initials: LY
authors.lastname: Al-Ahaidib
authors.forename: Osama Y
authors.initials: OY
authors.lastname: Al-Dirbashi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Al Amoudi
authors.forename: Moeen M A
authors.initials: MM
authors.lastname: Al-Sayed
authors.forename: Zuhair
authors.initials: Z
authors.lastname: Rahbeeni
authors.forename: Zuhair
authors.initials: Z
authors.lastname: Al-Hassnan
authors.forename: Abeer
authors.initials: A
authors.lastname: Al-Dbaas
authors.forename: Mohamed
authors.initials: M
authors.lastname: Al-Owain
authors.forename: Michelle
authors.initials: M
authors.lastname: Ni Luanaigh
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003512:Cyclohexanones / Q000627:therapeutic use; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D006537:Heptanoates / Q000652:urine*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D013058:Mass Spectrometry; D008875:Middle Aged; D015997:Neonatal Screening / Q000379:methods; D009579:Nitrobenzoates / Q000627:therapeutic use; D015203:Reproducibility of Results; D020176:Tyrosinemias / Q000188:drug therapy / Q000652:urine*
chemical_list: D003512:Cyclohexanones; D004791:Enzyme Inhibitors; D006537:Heptanoates; D009579:Nitrobenzoates; C020804:succinylacetone; C077073:nitisinone