The determination of oxalate in urine and urinary calculi by a new ion-chromatographic technique.

A new method is described for the measurement of oxalate in urine and urinary calculi using medium pressure ion-chromatography. The technique is simple, requires minimal sample preparation and only 20 min analysis time. The minimum detection limit for oxalate is 0.5 mumol/l in the diluted sample as applied to the analyser. The intra-run coefficient of variation for the chromatography stage alone is 3.8%. The overall intra-run and inter-run coefficients of variation, including the sampling and dilution of urine, are 6.5 and 8.3% respectively. The method compares well with an established colorimetric technique for the analysis of oxalate both in urine and in urinary calculi.