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Test Code HMETRU Heavy Metal/Creatinine Ratio, with Reflex, Urine

Important Note

Mayo test code HMCRU

Additional Codes

Sunrise Clinical Manager (SCM) Orderable:   Heavy Metals Random Urine

AllScripts (AEHR) Orderable:  Heavy Metals Screen, Random Urine

Specimen Required

Patient Preparation:

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

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

Supplies: Urine Tubes, 10 mL (T068)

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

Submission Container/Tube: Plastic, 10-mL urine tube (T068) or clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 6 mL

Collection Instructions:

1. Collect a random urine specimen.

2. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

Useful For

Preferred screening test for detection of arsenic, cadmium, mercury, and lead in random urine specimens

Profile Information

Test ID Reporting Name Available Separately Always Performed
ARSC Arsenic/Creatinine Ratio, U Yes, (order ARSCR) Yes
CDRC Cadmium/Creatinine Ratio, U Yes, (order CDRCR) Yes
HGRC Mercury/Creatinine Ratio, U Yes, (order HGRCR) Yes
PBRC Lead/Creatinine Ratio, U Yes, (order PBRCR) Yes
CDCR Creatinine Conc No Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
ASFRU Arsenic Fractionation, Random, U Yes No

Testing Algorithm

If arsenic concentration is greater than or equal to 35 mcg/L, then fractionation will be performed at an additional charge.


See Porphyria (Acute) Testing Algorithm in Special Instructions.

Method Name

ARSC, CDRC, HGRC, and PBRC: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

CDCR: Enzymatic Colorimetric Assay

Reporting Name

Heavy Metal/Creat Ratio, w/Reflex,U

Specimen Type


Specimen Minimum Volume

3 mL

Specimen Stability Information

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

Reject Due To









Clinical Information

Arsenic (As), lead (Pb), cadmium (Cd), and mercury (Hg) are well-known toxins and toxic exposures are characterized by increased urinary excretion of these metals.


Arsenic exists in a number of different forms; some are toxic while others are not. Toxic forms, which are typically encountered as a result of an industrial exposure, are the inorganic species As (+3) (As-III) and As (+5) (As-V) and the partially detoxified metabolites, monomethylarsine and dimethylarsine. The 2 most common nontoxic forms are arsenobetaine and arsenocholine. Arsenic toxicity affects a number of organ systems.


Lead toxicity primarily affects the gastrointestinal, neurologic, and hematopoietic systems.


Chronic exposure to cadmium causes accumulated renal damage.


Mercury is essentially nontoxic in its elemental form. However, once it is chemically modified to the ionized, inorganic species, Hg(++), it becomes toxic. Further bioconversion to an alkyl mercury, such as methyl Hg (CH[3]Hg[+]), yields a species of mercury that is highly selective for lipid-rich tissue, such as the myelin sheath, and is very toxic.

Reference Values


0-17 years: not established

≥18 years: <24 mcg/g creatinine



0-17 years: not established

≥18 years: <0.6 mcg/g creatinine



0-17 years: not established

≥18 years: <2 mcg/g creatinine



0-17 years: not established

≥18 years: <2 mcg/g creatinine

Day(s) and Time(s) Performed

Monday through Saturday; 7 p.m.

Analytic Time

1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

See Individual Test IDs

CPT Code Information






LOINC Code Information

Test ID Test Order Name Order LOINC Value
HMCRU Heavy Metal/Creat Ratio, w/Reflex,U In Process


Result ID Test Result Name Result LOINC Value
48544 Cadmium/Creatinine Ratio, U 13471-8
48546 Mercury/Creatinine Ratio, U 13465-0
48548 Lead/Creatinine Ratio, U 13466-8
CDCR Creatinine Conc 2161-8
48541 Arsenic/Creatinine Ratio, U 13463-5
48542 Arsenic Concentration w/Reflex 5586-3

NY State Approved

Northwell Health Laboratories Additional Information:

Computer Interface Code:

   PDM #  1459882