Measurement of urinary oxalic acid: a comparison of five methods.
OBJECTIVE
Five methods for oxalate analysis in urine are compared with respect to reliability, accuracy, and practicability.


RESULTS
Suppressed and unsuppressed ionchromatography, as well as the enzymatic Sigma-Kit, achieve low coefficients of variation for the within-batch imprecision (1.1-8.0%) and between-day imprecision (1.6-7.2%). The results of these methods are comparable and the mean recovery rate ranges between 99.7% and 100.9%. The enzymatic Boehringer-Kit gives higher CV (3.1-9.5%) and the results are lower than those obtained by the methods mentioned above; the recovery rate is sufficient (92.4%).


CONCLUSIONS
The handling of the chromatographic methods is very easy, whereas the enzymatic methods require more manual work. In relation to sample throughput, charges for the enzymatic methods are about twice as high as for the chromatographic methods. In respect to reliability and accuracy, the chromotropic acid method cannot be recommended (recovery rate 68%).
Hesse
A
A
Department of Urology, University of Bonn, Germany.
Bongartz
D
D
Heynck
H
H
Berg
W
W
D002852:Chromatography, Ion Exchange / Q000191:economics / Q000379:methods; D003365:Costs and Cost Analysis; D006801:Humans; D007124:Immunoenzyme Techniques / Q000191:economics; D007202:Indicators and Reagents; D009282:Naphthalenesulfonates; D010070:Oxalates / Q000652:urine*; D019815:Oxalic Acid; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D016482:Urinalysis / Q000379:methods
D007202:Indicators and Reagents; D009282:Naphthalenesulfonates; D010070:Oxalates; D011933:Reagent Kits, Diagnostic; D019815:Oxalic Acid; C020996:chromotropic acid