• If patient is taking diuretics, antihypertensive drugs, cyclic progestational agents, estrogen, or licorice, results for aldosterone may not be interpretable
• Patient should be on a diet containing 135 mmol (3 g) sodium per day for at least two weeks and preferably 30 days prior to testing

24-hr urine collection container, no additive

1. Instruct the patient to void at 8 AM and discard the specimen.
2. Then collect all urine including the final specimen voided at the end of the 24-hour collection period (ie, 8 AM the next morning).
3. Screw the lid on securely. Transport the specimen promptly to the laboratory.
4. Label container with patient's name, date, and time.

How to collect a 24-hr urine sample

1. Measure and record the total urine volume
2. Include the total volume on the request form
3. Include the total volume on the request form
4. Mix well
5. Transfer  a 10mL (minimum 1.0mL) aliquot to a Transfer vial/tube with cap - 12mL (LabCorp)

pH must be 4 to 8

Transfer vial/tube with cap - 12mL (LabCorp)

Refrigerated (preferred) - 14 days

Ambient - 7 days

Frozen - 14 days

Freeze/thaw cycles - stable x3

• Incomplete 24-hour collection
• Original container with pH <2

Liquid chromatography/tandem mass spectrometry (LC/MS-MS)

Pediatric:
0 - 3 days:           0.00−5.00 μg/24 hrs
4 days - 10 years: 0.00−8.00 μg/24 hrs
>10 years:           0.00−19.00 μg/24 hrs

Adult:
Low sodium intake:     20.00−80.00 μg/24 hrs
Normal sodium intake:  0.00−19.00 μg/24 hrs
High sodium intake:      0.00−12.00 μg/24 hrs