Clinical Chemistry AACC Online Job Center
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 37: 1229-1235, 1991;
This Article
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wilson, D. M.
Right arrow Articles by Liedtke, R. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wilson, D. M.
Right arrow Articles by Liedtke, R. R.

Clinical Chemistry, Vol 37, 1229-1235, Copyright © 1991 by American Association for Clinical Chemistry

Modified enzyme-based colorimetric assay of urinary and plasma oxalate with improved sensitivity and no ascorbate interference: reference values and sample handling procedures

DM Wilson and RR Liedtke
Mayo Clinic, Rochester, MN 55905.

The measurement of oxalate in urine and plasma continues to be difficult, particularly in the presence of ascorbate. We have modified and validated a colorimetric assay involving the use of oxalate oxidase (EC 1.2.3.4). Modification of an HPLC spectrophotometric detector improved sensitivity (to as much as 1000-fold that of conventional spectrophotometers) and allowed measurement of oxalate concentrations less than 1 mumol/L. This provided more than enough sensitivity for measurement of normal concentrations of plasma oxalate. We established reference values for oxalate concentrations in urine and plasma, studied sample handling, and established conditions to avoid ascorbate interference in urine and plasma measurements. Mean analytical recovery of [14C]oxalate from plasma to the filtrate was 86 (SD 10)%; recovery of unlabeled oxalate from filtrate was 87 (SD 9)%. Urinary oxalate excretion rates in apparently healthy controls were 0.11-0.46 mmol/24 h. Plasma concentrations in control subjects were 2.5 (SD 0.7) mumol/L, similar to concentrations determined by recent gas chromatographic and isotope dilution methods. Frozen and acidified urine samples showed no interference from ascorbate when excess ascorbate was avoided. Ingestion of 2 g of ascorbate daily did not increase urinary oxalate in healthy control subjects, but during storage ascorbate was converted to oxalate in all conditions tested.


The following articles in journals at HighWire Press have cited this article:


Home page
 Clin. Chem.Home page
P. M. Ladwig, R. R. Liedtke, T. S. Larson, and J. C. Lieske
Sensitive Spectrophotometric Assay for Plasma Oxalate
Clin. Chem., December 1, 2005; 51(12): 2377 - 2380.
[Full Text] [PDF]

Home page
 JAMAHome page
M. Levine, S. C. Rumsey, R. Daruwala, J. B. Park, and Y. Wang
Criteria and Recommendations for Vitamin C Intake
JAMA, April 21, 1999; 281(15): 1415 - 1423.
[Abstract] [Full Text] [PDF]

Home page
 CLIN PEDIATRHome page
M. Santos-Victoriano, B. H. Brouhard, and R. J. Cunningham III
Renal Stone Disease in Children
Clinical Pediatrics, October 1, 1998; 37(10): 583 - 599.
[Abstract] [PDF]

Home page
 NEJMHome page
D. S. Milliner, J. T. Eickholt, E. J. Bergstralh, D. M. Wilson, and L. H. Smith
Results of Long-Term Treatment with Orthophosphate and Pyridoxine in Patients with Primary Hyperoxaluria
N. Engl. J. Med., December 8, 1994; 331(23): 1553 - 1558.
[Abstract] [Full Text]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1991 by the American Association for Clinical Chemistry.