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Test ID CRCRU Chromium/Creatinine Ratio, Random, Urine

Ordering Guidance

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.

Specimen Required

Supplies: Urine Tubes, 10 mL

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

Submission Container/Tube: Plastic vial or clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 3 mL

Collection Instructions:

1. Collect a random urine specimen.

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

Useful For

Detecting chromium exposure

Profile Information

Test ID Reporting Name Available Separately Always Performed
CRCRR Chromium/Creat Ratio, U No Yes
CRETR Creatinine, Random, U No Yes

Method Name

CRCRR: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

CRETR: Enzymatic Colorimetric Assay

Reporting Name

Chromium/Creat Ratio, Random, U

Specimen Type


Specimen Minimum Volume

0.7 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  14 days

Reference Values

0-17 years: Not established

>17 years: <0.8 mcg/g Creatinine

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
CRCRU Chromium/Creat Ratio, Random, U 13464-3


Result ID Test Result Name Result LOINC Value
CRETR Creatinine, Random, U 2161-8
607759 Chromium/Creat Ratio, U 13464-3

Day(s) Performed

Tuesday, Wednesday, Friday

Report Available

1 to 4 days