PHOSPHORUS, URINE, 24 HOUR

Message

There is a diurnal variation in urine phosphate excretion with the highest output occurring in the afternoon.

Submit the Total Volume in mLs.

Test Code

PHOUN

CPT Codes
84105

Includes

Phosphorus

Preferred Specimen

24 Hour Urine Container without preservative
(aliquot or transfer urine into a transfer tube and note the total volume)

Minimum Volume

5 mL aliquot

Instructions

Mix the specimen well and measure the 24-Hour volume

Note the total volume in mLs.

Pour off 20 mL of urine into a separate plastic screw-cap container.

Refrigerate if not tested immediately.

Sample will be acidified by Central Lab staff with 6N HCL to a pH <2 prior to testing.

Transport Container

Plastic screw-cap container

Transport Temperature

Refrigerate

Specimen Stability

Urine may contain larger quantities of organic phosphates, which can decompose upon exposure to elevated temperatures. Keep refrigerated.
2-8°C up to 7 days; once acidified, urine is stable up to 6 months.

Methodology
Colorimetric

Setup Schedule

M, T, W, Th, F, Sa, Sun

Report Available

Same day tested by performing laboratory.

Reference Range

Age	g/24 Hours (Urine)
Adults	0.3 - 1.3
Children	1.5 - 0.8

Clinical Significance

Measurements of inorganic phosphorus are used in the diagnosis and treatment of various disorders including parathyroid gland and kidney diseases, and Vitamin D imbalance.

Performed By
Alverno Laboratories

Performing Laboratory
Alverno Central Lab
NCHB1 (Chemistry, Beckman AU)

Additional Information
24 Hour Urine Collection

Last Updated: January 23, 2025

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.