Development of a reference method for determining urinary oxalate by means of isotope dilution-mass spectrometry (ID-MS) and its usefulness in testing existing assays for urinary oxalate.
An accurate and reproducible GC-MS reference method for determining urinary oxalate is presented. With forty 24-h urines, comparisons were made between this reference method and four other existing procedures: a GC method, an HPLC method and two enzymatic assays. The results of the first two methods were in accordance with the GC-MS method. The performance of the enzymatic kits was less satisfactory. The use of a GC-MS reference method in evaluating existing and newly developed methods is recommended.
Central Laboratory for Clinical Chemistry, University Hospital, Groningen, The Netherlands.
W
W
Koolstra
B G
BG
Wolthers
M
M
Hayer
H
H
Elzinga
D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D010070:Oxalates / Q000652:urine*; D019815:Oxalic Acid; D011933:Reagent Kits, Diagnostic; D012015:Reference Standards
D010070:Oxalates; D011933:Reagent Kits, Diagnostic; D019815:Oxalic Acid