Citric Acid, 24-Hour Urine with Creatinine

For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

Test Code

CPT Codes
82507, 82570

CPT code 81050 may be added at an additional charge for volume measurement

Preferred Specimen
10 mL of a 24-hour urine collected in a 24 hour urine container

Minimum Volume
1.5 mL

Do not include first morning specimen; collect all subsequent voiding's.
The last sample collected should be the first morning specimen voided the following morning at the same time as the previous morning's first voiding.
Specify 24-hour total volume on container and test requisition.

Transport Temperature
Refrigerated (cold packs)

Specimen Stability
Room temperature: 8 hours
Refrigerated: 30 days
Frozen: 60 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Received room temperature • Acidified urine

Spectrophotometry (SP)

Setup Schedule
Monday-Friday Evening Report available: Next Day

Reference Range
See Laboratory Report

Clinical Significance
Citrate binds to calcium and inhibits kidney stone formation. Thus, low concentrations of citrate may lead to kidney stone formation. This is the most important risk factor to kidney stone formation in children. The treatment of calcium stones involves increasing urinary citrate excretion.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

Last Updated: December 7, 2021

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.