Citrate in urine determined with a new citrate lyase method.

摘要: An enzyme-spectrophotometric method to determine citrate in biological fluids is proposed, based on lyase-catalyzed and phenylhydrazine reactions. The enzyme converts into oxaloacetate, which, the presence of phenylhydrazine, transformed corresponding phenylhydrazone. ultraviolet-absorbing product determined by absorbance measurement at 330 nm. more precise twice as sensitive traditional lyase and, because it does not require use additional enzymes coenzymes, cheaper simpler. Mean analytical recovery averaged 100.7% +/- 2.2%, imprecision (CV) assay for 0.96 mmol/L (urine) was 2.0%, lower limit quantification 0.08 mmol/L. Results correlated well with those both ion-chromatographic methods.