Testing Laboratory
Auckland Te Toka Tumai | Auckland HospitalDepartment
Chemical Pathology
Delphic Registration Code (Alpha Code)
UMG
Test Code (Numeric Code)
0268
Laboratory Handling
Phlebotomy
1= A 24 hr urine collected in acid is the recommended sample for adults. 2= A spot urine in a plain container (for magnesium/creatinine ratio). Request magnesium and creatinine.
Sample Stability
3 days at 15-25°C 3 days at 2-8°C 1 year at -20°C
Synonyms
Urine Magnesium, Urine Mg+
Turnaround Time
3 hours
Specimen Type
- 24hr Urine
- Urine
Specimen Requirements
Tube/Container Type:
Preferred
- Acidified 24hr Urine Container
Acceptable
- BD Urine Tube (no additive)
Paediatric Specimen Requirements
Tube/Container Type:
Preferred
- Acidified 24hr Urine Container
Acceptable
- BD Urine Tube (no additive)
Additional Specimen Information
Laboratory Notes
Non acidified 24-hour urines for Magnesium can be acidified post collection. The sample must be mixed well after the acid has been added and left for an hour before mixing again and aliquotting for sampling.
Casual urines without acidification are acceptable as is for up to 12 hours post collection. Samples older than this must be acidified first. The sample must be mixed well after the acid has been added and left for an hour before mixing again and aliquotting for sampling.
Last updated: 30/03/2026