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Test ID HMU24 Heavy Metals Screen, with Reflex, 24 Hour, Urine

Specimen Required

1. High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.

2. Patient should not eat seafood for a 48-hour period prior to start of, or during, collection.

Supplies: Urine Tubes, 10 mL (T068)

Collection Container/Tube: Clean, plastic aliquot container with no metal cap or glued insert

Submission Container/Tube: Plastic, 10-mL urine tube

Specimen Volume: 10 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. Refrigerate specimen within 4 hours of completion of 24-hour collection.

3. See Trace Metals Analysis Specimen Collection and Transport for complete instructions.

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

Useful For

Detecting arsenic, cadmium, mercury, and lead exposure and toxicity using 24-hour urine specimens

Profile Information

Test ID Reporting Name Available Separately Always Performed
ASHU Arsenic, 24 Hr, U Yes, (order ASU24) Yes
CDHMU Cadmium, 24 Hr, U Yes, (order CDU) Yes
HGHU Mercury, 24 Hr, U Yes, (order HGU) Yes
PBHU Lead, 24 Hr, U Yes, (order PBU) Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
SPASU Arsenic Speciation, 24 Hr, U Yes No

Testing Algorithm

If arsenic concentration is greater than or equal to 10 mcg/L, then speciation will be performed at an additional charge.

Method Name

Triple Quadrupole Inductively Coupled Plasma-Mass Spectrometry (ICP-MS/MS)

Reporting Name

Heavy Metal Scrn w/Reflex, 24 Hr, U

Specimen Type


Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 7 days
  Frozen  7 days

Reference Values


0-17 years: Not established

≥18 years: <35 mcg/24 h



0-17 years: Not established

≥18 years: <0.7mcg/24 h



0-17 years: Not established

≥18 years: <2 mcg/24 h

Toxic concentration: >50 mcg/24 h


The concentration at which toxicity is expressed is widely variable between patients.

50 mcg/24 h is the lowest concentration at which toxicity is usually apparent.



0-17 years: Not established

≥18 years: <2 mcg/24 h

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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 US Food and Drug Administration.

CPT Code Information





LOINC Code Information

Test ID Test Order Name Order LOINC Value
HMU24 Heavy Metal Scrn w/Reflex, 24 Hr, U 94575-8


Result ID Test Result Name Result LOINC Value
8678 Cadmium, 24 Hr, U 5612-7
48539 Arsenic, 24 Hr, U 5587-1
92408 Mercury, 24 Hr, U 6693-6
92409 Lead, 24 Hr, U 5677-0
TIME4 Collection Duration 13362-9
92215 Total Arsenic Concentration 21074-0
VL16 Total Volume 3167-4

Urine Preservative Collection Options

Note: The addition of preservative or application of temperature controls must occur within 4 hours of completion of the collection.







50% Acetic Acid


Boric Acid


Diazolidinyl Urea


6M Hydrochloric Acid


6M Nitric Acid


Sodium Carbonate