Ammonium, 24 Hour, Urine
Use
Measurement of ammonium in a 24‑hour urine collection assists in the evaluation of acid–base disorders. Low urine ammonium in the setting of acidosis suggests renal tubular acidosis, while high ammonium with low urinary pH suggests gastrointestinal bicarbonate losses. It is also valuable in the treatment and monitoring of kidney stone patients—helping guide citrate therapy dosing to avoid unwanted rise in urine pH and calcium phosphate stone risk.
Special Instructions
Requires 24‑hour urine collection with preservative or refrigeration. 24‑Hour volume in milliliters is required. If not ordering electronically, send Renal Diagnostics Test Request (T830). Refer to 'Urine Preservatives‑Collection and Transportation for 24‑Hour Urine Specimens' for collection guidance.
Limitations
Specimens with pH >8 may indicate bacterial contamination and will be cancelled; specimens should not have pH adjusted. Reference values are not established for patients under 18 or over 77 years. The test is modified from the manufacturer’s instructions, performance was determined under CLIA, and it is not cleared or approved by the FDA.
New York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 25308-8
- 25308-8
- 13362-9
- 3167-4
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
4 mL
Minimum Volume
1 mL
Container
Plastic vial
Collection Instructions
Add 5 mL of diazolidinyl urea (Germall) at start of collection or refrigerate during and after; collect urine for 24 hours; aliquot into plastic vial.
Causes for Rejection
pH > 8 indicating bacterial contamination
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Ambient: 72 hours |
| Refrigerated | 14 days |
| Frozen | 14 days |