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HelpTest Code SULFU Sulfate, 24 Hour, Urine
Reporting Name
Sulfate, 24 Hr, UUseful For
Assessing the nutrition intake of animal protein
The calculation of urinary supersaturation of various crystals or stones
Method Name
High-Pressure Ion Chromatography (HPIC)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
UrineNecessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Container/Tube: Plastic, 5-mL urine tube
Specimen Volume: 4 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Collection instructions with no preservative:
-Specimen must be kept refrigerated during and after collection.
3. Collection instructions with preservative:
 a. If preservative is not added before collection, the specimen must be kept refrigerated until preservative is added.
 b. Preservative must be added within 4 hours of the end of collection.
4. Specimen pH should be between 4.5 and 8 and will stay in this range if kept refrigerated. Specimens with pH >8 indicate bacterial contamination, and testing will be cancelled. Do not attempt to adjust pH as it will adversely affect results.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 14 days | |
| Frozen | 14 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Special Instructions
Reference Values
7-47 mmol/24 hours
Day(s) Performed
Monday through Friday
CPT Code Information
84392
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| SULFU | Sulfate, 24 Hr, U | 26889-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| SLF_U | Sulfate, 24 Hr, U | 26889-6 |
| TM89 | Collection Duration | 13362-9 |
| VL71 | Urine Volume | 3167-4 |
| SUL_C | Sulfate Concentration, 24 Hr, U | 12920-5 |
Clinical Information
Urinary sulfate is a reflection of dietary protein intake, particularly meat, fish, and poultry, which are rich in sulfur-containing amino acids methionine and cysteine. Urinary sulfate can be used to assess dietary protein intake for nutritional purposes. A protein-rich diet has been associated with an increased risk for stone formation, possibly due, in part, to an increase in urinary calcium excretion caused by acid production from metabolism of sulfur-containing amino acids.(1,2) Indeed, urinary sulfate excretion is higher in patients who have kidney stones than in individuals who do not form stones. Thus, urinary sulfate excretion may provide an index for protein-induced calciuria.(1)
Sulfate is a major anion in the urine that has significant affinity for cations and modulates the availability of cations for reacting with other anions in the urine. It thus is an important factor of urinary supersaturation(3) for various crystals or stones such as calcium oxalate, hydroxyapatite, and brushite. For example, a high sulfate concentration may modulate the availability of calcium for reacting with oxalate and thus affect the propensity for calcium oxalate stone or crystal formation. Urinary sulfate also has a major impact on buffering or providing hydrogen ions and as such modulates the supersaturation of uric acid.
Interpretation
Urinary sulfate is a reflection of dietary protein intake, particularly of meat, and thus can be used as an index of nutritional protein intake.
It also is used in the calculation of urinary supersaturation of various crystals or stones.
Cautions
No significant cautionary statements
Method Description
A high pressure ion chromatography system (HPICS) utilizes an anion exchange column to separate sulfate from other anions present in urine. Detection of sulfate is done by conductivity change as eluent flows through a conductivity cell of a conductivity detector. The Thermo IC system is operated through a PC computer using thermo Chromeleon 7 software.(Christison T, Lopez L. Determination of Inorganic Anions in Acid Rain Using a Dedicated High-Pressure Capillary Ion Chromatography System. Technical Note 124 Thermo Scientific; 2016)