Ordering Recommendation

Use to determine the cause of acidosis. May aid in diagnosing and monitoring kidney stones. A 24-hour urine collection of 300 mL or greater is required. To submit a random urine or 24-hour collection with a total volume of less than 300 mL, contact ARUP Client Services for further assistance.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

24-hour urine. Refrigerate during collection or add 5 mL of diazolidinyl urea (Germall) as preservative at start of collection.

Specimen Preparation

From a well-mixed 24-hour collection, transfer 4 mL urine to an ARUP standard transport tube. (Min: 1 mL). Collection duration and urine volume must be provided for testing.Test is not performed at ARUP; separate specimens must be submitted when multiple tests are ordered.

Storage/Transport Temperature

Refrigerated. Also acceptable: Frozen.

Unacceptable Conditions

Specimens with pH >8 may indicate bacterial contamination and testing will be canceled. Do not attempt to adjust pH as it will adversely affect results. Collection duration and urine volume must be provided for testing. Total collection volume must be greater than 300 mL.


Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 2 weeks


Quantitative Enzymatic Assay




3-5 days

Reference Interval

By Report

Interpretive Data

Compliance Category

Performed by non-ARUP Laboratory


Reference values have not been established for patients less than 18 years and greater than 77 years of age. The presence of sulfasalazine, sulfapyridine, or temozolomide may lead to false results.

Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
3004263 Ammonium, 24 Hour Urine 25308-8
3004264 Ammonium Collection Duration 13362-9
3004265 Ammonium Urine Volume 3167-4
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Ammonia
Ammonium, 24-Hour Urine

Mayo Clinic Laboratories