Aliquot from a well-mixed 24 hour urine collected without a preservative.
Indicate the collection time.
The total volume collected must be measured, recorded, and included with the test request.
If multiple tests needed on urine, acceptable alternate preservatives include 7 g sulfamic acid, 20 mL 6N HCl, 25 mL 33% acetic acid, 10 g boric acid, or 5 g sodium carbonate.