title: Methylmalonic acid quantification by stable isotope dilution gas chromatography-mass spectrometry from filter paper urine samples.
abstract: A specific method for quantification of methylmalonic acid (MMA) from urine samples dried onto filter paper is described. The method involves stable isotope dilution gas chromatography-mass spectrometry with [methyl-2H3]-MMA as the internal standard. MMA is stable in dry paper samples stored at room temperature for at least 2 weeks. The extraction efficiency of MMA from paper was 56-58%. The concentration of urinary MMA in dried filter paper specimens from 190 normal controls was 1.21 +/- 1.34 (mean +/- SD) mmol/mol of urinary creatinine. Age-related reference values are also reported. The concentrations, normalized to the urinary creatinine concentration, decrease with age. The applicability of this method to rapid screening for cobalamin (vitamin B12)-related disorders and methylmalonic aciduria is demonstrated.
authors.affiliation: Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA.
authors.forename: M T
authors.initials: MT
authors.lastname: McCann
authors.forename: M M
authors.initials: MM
authors.lastname: Thompson
authors.forename: I C
authors.initials: IC
authors.lastname: Gueron
authors.forename: B
authors.initials: B
authors.lastname: Lemieux
authors.forename: R
authors.initials: R
authors.lastname: Giguère
authors.forename: M
authors.initials: M
authors.lastname: Tuchman
mesh_terms: D000293:Adolescent; D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors / Q000652:urine; D002648:Child; D002675:Child, Preschool; D003903:Deuterium; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D008764:Methylmalonic Acid / Q000652:urine*; D010209:Paper; D012016:Reference Values; D014806:Vitamin B 12 Deficiency / Q000652:urine
chemical_list: D008764:Methylmalonic Acid; D003903:Deuterium