ARUP's Laboratory Test Directory

Oxalate, Urine : 0020482

Mnemonic: UOXAL

Methodology: Quantitative Spectrophotometry
Performed: Mon-Fri
Reported: 1-4 days
Specimen Required: Patient Prep: Patient should avoid ingestion of vitamin C prior to collection.

Collect: 24-hour urine. Refrigerate during collection.

Specimen Preparation: Thoroughly mix entire collection (24-hour or random) in one container.
Then, perform one of the two processing options below:
Option 1:
a. Adjust pH to 1.5-2 with 6M HCl (approximately 10 mL HCl/24-hour specimen based on normal adult output of 1000-2000 mL/24 hours. Pediatric specimens will require less than 10 mL to reach correct pH).
b. Transfer 4 mL aliquot of adjusted urine to an ARUP Standard Transport Tube. (Min: 1.5 mL)
c. Record total volume and collection time interval on transport tube and test request form. This information is required for test interpretation.
Option 2:
a. Transfer 4 mL aliquot from the well-mixed 24-hour urine collection (ARUP supply #48098) to an ARUP Standard Transport Tube with 12 mg Sulfamic Acid. (Min: 1.5 mL)
b. Record total volume and collection time interval on transport tube and test request form. This information is required for test interpretation.

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Specimens with no preservative or with a pH greater than 3.

Stability (collection to initiation of testing): Ambient: 4 hours; Refrigerated: 1 week; Frozen: 1 month
Reference Interval:
           
 
Test Number Components Reference Interval
 Creatinine, Urine - per 24h  
 
Age Male Female
3-8 years 140-700 mg/d 140-700 mg/d
9-12 years 300-1300 mg/d 300-1300 mg/d
13-17 years 500-2300 mg/d 400-1600 mg/d
18-50 years 1000-2500 mg/d 700-1600 mg/d
51-80 years 800-2100 mg/d 500-1400 mg/d
81 years and older 600-2000 mg/d 400-1300 mg/d
 Oxalate, Urine0-12 years: 13-38 mg/d
Male 13 years and older: 7-44 mg/d
Female 13 years and older: 4-31 mg/d

Interpretive Data: Reference intervals for random urine samples (mg/L) are not available.
Note: Since vitamin C (ascorbic acid) quickly degrades to oxalate in nonacidified urine, patients should consider refraining from vitamin C supplements during and for 48 hours prior to urine collection for oxalate.
CPT Code(s): 83945