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Test Code CATU Catecholamine Fractionation, Free, 24 Hour, Urine

Important Note

Evaluation for catecholamines in urine is no longer recommended at Seattle Children's.  Measurements of either plasma free metanephrines or 24 hour urinary fractionated metanephrines are recommended for screening for pheochromocytomas and paragangliomas.

Reporting Name

Catecholamine Fract, Free, U

Useful For

An auxiliary test to fractionated plasma and urine metanephrine measurements in the diagnosis of pheochromocytoma and paraganglioma


An auxiliary test to urine vanillylmandelic acid and homovanillic acid determination in the diagnosis and follow-up of patients with neuroblastoma and related tumors

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Advisory Information

This assay is of greatest value when the specimen is collected during a hypertensive episode.


Unless the purpose of the measurement is drug monitoring, discontinue any epinephrine, norepinephrine, or dopamine injections or infusions for at least 12 hours before specimen draw.


Do not perform the test on patients withdrawing from legal or illegal drugs known to cause rebound catecholamine release during withdrawal (see Cautions for details)

Necessary Information

24-Hour volume is required.

Specimen Required

Patient Preparation: Discontinue drugs that release or hinder metabolism of epinephrine, norepinephrine, or dopamine for at least 1 week before obtaining the specimen (see Cautions for details). If this is not possible for medical reasons, contact the laboratory to discuss whether a shorter drug-withdrawal period may be acceptable.

Supplies: Plastic, 10-mL urine tube (T068)

Specimen Volume: 2 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. Add 25 mL of 50% acetic acid as preservative at start of collection. Use 15 mL of 50% acetic acid for children less than 5 years old. This preservative is intended to achieve a pH of between approximately 2 and 4.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.

Specimen Minimum Volume

1.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 7 days
  Frozen  14 days
  Ambient  7 days

Reference Values


 <1 year: <11 mcg/24 hours

1 year: 1-17 mcg/24 hours

2-3 years: 4-29 mcg/24 hours

4-6 years: 8-45 mcg/24 hours

7-9 years: 13-65 mcg/24 hours

≥10 years: 15-80 mcg/24 hours



 <1 year: <2.6 mcg/24 hours

1 year: <3.6 mcg/24 hours

2-3 years: <6.1 mcg/24 hours

4-9 years: 0.2-10.0 mcg/24 hours

10-15 years: 0.5-20.0 mcg/24 hours

≥16 years: <21 mcg/24 hours



<1 year: <86 mcg/24 hours

1 year: 10-140 mcg/24 hours

2-3 years: 40-260 mcg/24 hours

≥4 years: 65-400 mcg/24 hours


For SI unit Reference Values, see

Day(s) and Time(s) Performed

Monday through Saturday; 8 a.m.

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
CATU Catecholamine Fract, Free, U In Process


Result ID Test Result Name Result LOINC Value
TM48 Collection Duration 13362-9
VL46 Urine Volume 3167-4
2106 Norepinephrine 2668-2
2107 Epinephrine 2232-7
2108 Dopamine 2218-6

Reject Due To









Method Name

High-Performance Liquid Chromatography (HPLC)
Includes unconjugated epinephrine, norepinephrine, and dopamine

Method Description

A 1-mL aliquot of a 24-hour urine collection preserved in acid is absorbed on aluminum oxide at an alkaline pH and eluted with acid. An aliquot of the eluate is injected onto a high-performance reverse-phase paired ion-chromatography column where the catecholamines are resolved into individual components. The catechol is oxidized electronically to an O-quinone. The current generated at the detector is converted by amplifier to a voltage signal and an XY recording is generated.(Jiang NS, Machacek D: Measurement of catecholamines in blood and urine by liquid chromatography with amperometric detection. In Progress in HPLC. Vol 2. Edited by Parvez. VNU Science Press, 1987, pp 397-426; Moyer TP, Jiang NS, Tyce GM, Sheps SG: Analysis for urinary catecholamines by liquid chromatography with amperometric detection: methodology and clinical interpretation of results. Clin Chem 1979;25:256-263)

Urine Preservative Collection Options







6N HCl


50% Acetic Acid








Boric Acid






If not ordering electronically, complete, print, and send an Oncology Test Request Form (T729) with the specimen (