Lab Test

Citric Acid, Urine 24 Hour

Citric Acid, Urine, Urine Citrate

Test Codes

Antrim #13205, EPIC: LAB5853, SOFT: CIT24


Please refer to the Specimen Collection Manual for instructions on 24 Hour Urine Collection:

Specimen Collection Criteria

Collect (preferred specimen): 24 hour urine sample with no preservatives.

  • Keep 24 hour urine specimen iced or refrigerated during collection.
  • Include start and end dates and times for the collection period on the specimen container.
Urine Preservative Options
No Preservative
6N Hydrochloric Acid
Boric Acid (10g)
Sodium Carbonate
50% Acetic Acid

Physician Office/Draw Specimen Preparation

Maintain specimens refrigerated (2-8°C or 36-46°F) prior to transport.

Preparation for Courier Transport

Transport: Entire 24 hour urine collection, refrigerated (2-8°C or 36-46°F).

Rejection Criteria

  • Random urine specimens.
  • Samples not kept refrigerated (2-8°C or 36-46°F).
  • Samples not collected and processed as indicated.

In-Lab Processing

Measure total volume of 24 hour urine specimen. Record total volume and collection start and end dates and times in the LIS system. Aliquot a minimum of 10 mL from the well-mixed 24 hour urine collection and centrifuge. Refrigerate aliquot prior to analysis.


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 14 days

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days


Royal Oak Special Testing Laboratory


Varies, once per week.
Results available within 7 days.

Reference Range

320-1240 mg/24 hr.

Test Methodology

UV-Method 340 nm.


Decreased levels of urinary citrate (hypocitraturia) are associated with increased risk of renal stone formation.

Clinical Utility

This assay aids in determining the risk of formation of renal calcium stones. It is also used to monitor the results of therapy in patients with calcium stones or renal tubular acidosis. It is determined as part of the Stone Former Panel.

CPT Codes

LOINC: 6687-8, 21203-5


Last Updated


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