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Test Code 24CT Citrate, urine, 24 hr

Important Note

Urine must be acidified with 6N HCL OR preserved with 3.0 g Thymol during collection. Please collect 24 hr urine bottle from Clinical Chemistry

Laboratory Code

LAB377

Specimen Requirements

Specimen Type: 24 hr urine

Container/Tube: The following types of 24 hr urine containers are acceptable:

  • 6N HCL
  • 3.0 g Thymol

 

Volume: 4000.0 mL
Minimum Volume: 20.0 mL 

Collection Instructions: Urine must be acidified with 6N HCL OR 3.0 g Thymol during collection.
 

Please refer to NUH's Urine Preservative Guide

Specimen Stability

Specimen Type 24 hr urine
Ambient Not available
Refrigerate 4 days (preferred)
Frozen 2 weeks

Methodology

Enzymatic Colourimetric Assay

Days and Times Performed

Tuesday, TAT 2 - 8 days

Specimen Condition

Haemolysis Not Applicable
Icterus Not Applicable
Lipaemia Not Applicable
Others: Urine not preserved with 6N HCL OR 3.0 g Thymol during collection Reject 

Reference Interval

Age Male Female
2 – < 7 yrs 177 – 591 mg/day/1.73m2 218 – 651 mg/day/1.73m2
7 – < 13 yrs 162 – 600 mg/day/1.73m2 253 – 657 mg/day/1.73m2
13 – < 18 yrs 130 – 476 mg/day/1.73m2 248 – 729 mg/day/1.73m2
≥ 18 yrs 320 – 1240 mg/day

Reference ranges provided are based on 5th to 50th percentile. Patients at risk of nephrolithiasis should ideally have urine citrate excretion ≥ 50th percentile.

Testing Laboratory

National University Hospital
Clinical Chemistry, 67724399

Useful For

Investigation of renal calculi

Service Code

31152

LOINC Code Information

Urine volume, total 3167-4
Citrate, urine 34266-7
Citrate, urine, 24 hr 6687-8

Update

Last updated 24/02/2025