Citric acid, random urine-994
Test info
Citrate excretion, random urine
A timed 24-hour urine collection is the preferred specimen for measuring and interpreting this urinary analyte. Random collections normalized to urinary creatinine may be of some clinical use in patients who cannot collect a 24-hour specimen, typically small children.
The mean urinary citrate excretion rate in patients with idiopathic calcium urolithiasis has been found to be significantly lower than that of control groups. Hypocitraturia is common in patients with urolithiasis resulting from renal tubular acidosis and in patients with enteric hyperoxaluria. Citrate excretion is low in renal insufficiency.
Specimen
Transfer sample to a Urine Monovette with pH stabilizer
If a Urine Monovette with pH stabilizer is unavailable, transfer the specimen to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp) and freeze
Specimen preserved in Urine Monovette with pH stabilizer
Refrigerated (preferred) - 29 days
Ambient - 29 days
Frozen - 49 days
Freeze/thaw cycles - Stable x5
Unpreserved specimen
Frozen (strict) - 49 days
- If specimen is not Frozen; pH must be between 1-3
Performance
Nuclear magnetic resonance (NMR) or Enzymatic
Clinical and Interpretive info
| Gender | Age (years) | Range (mg/L) |
| Male | <40 | 9 - 864 |
| ≥40 | 7 - 1130 | |
| Female | <40 | 40 -1930 |
| ≥40 | 10 -1560 |
- Citrate: Boric Acid used as a preservative (Boric acid ≥1250 mg/dL may cause citrate results to be reduced by approximately 30%)
- Multivitamin ≥397.5 mg/dL (estimated as 1 pill per day) may cause citrate results to be unmeasurable.
- Results of interference testing may not be representative of in-vivo characteristics of multivitamin consumption.