| Ordering Code | 531 |
|---|---|
| Test Name | Magnesium, 24 Hr Urine |
| Alias | 24 Hr Urine Magnesium |
| Preferred Specimen | Urine, 24 Hour |
| Preferred Container | 24 Hour Urine Container |
| Optimum Volume | 1 mL |
| Collection Instructions | Keep refrigerated during collection 24 Hour collections: Do not include first morning specimen; collect all subsequent voidings. The last sample collected should be the first morning specimen voided the following morning at the same time as the previous morning first voiding. Record entire 24 Hr Volume on container and requisition No preservatives added. |
| Handling Instructions | Send a well-mixed, 50 mL aliquot specimen Processing: Adjust pH to 1 with concentrated HCl. If precipitate forms, shake, mix, acidify, and warm to 60 C to dissolve. |
| Transport Requirements | Oahu: Refrigerated Airline: Refrigerated |
| Specimen Stability | Refrigerated: 3 Days Frozen: 1 Year |
| Rejection Criteria | Specimen older than stability limits |
| Avail. Stat | NO |
| Analytic Time | 1 Day |
| Methodology | Xylidyl Blue |
Reference range(s)
The reference ranges listed below are valid on this date of August 15, 2025.
| Component | Age | Male Norm | Male Critical Low | Male Critical High | Female Norm | Female Critical High | Female Critical Low | Units | Add'l info |
|---|---|---|---|---|---|---|---|---|---|
| Total Volume | ALL | mL | See report. | ||||||
| Total Time | ALL | minutes | See report. | ||||||
| 24-Hr Urine Magnesium | ALL | 24-255 | 24-255 | mg/24hr | |||||
| Magnesium, Urine | ALL | mg/dL | See report. |