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22336 Arsenic w/Reflex, 24 Hr Urine (ASU24)

Arsenic w/Reflex, 24 Hr Urine (ASU24)
Test Code: ARUSO
Synonyms/Keywords
Arsenic (As), As (Arsenic)
Test Components

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

Useful For
​Preferred screening test for detection of arsenic exposure using 24-hour urine specimens
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
Urine​ Clean, plastic urine container with no metal cap or glued insert​ 10 mL​ 3 mL​
Collection Processing Instructions
​Submit sample in a plastic, 10-mL urine tube or clean, plastic aliquot container with no metal cap or glued insert.
1. Collect urine for 24 hours.
2. Refrigerate specimen within 4 hours of completion of 24-hour collection.
Additional Information:
1. 24-Hour volume is required.
2. 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.
3. Patient should not eat seafood for a 48-hour period prior to start of collection. 
Specimen Stability Information
Specimen Type Temperature Time
Urine​ ​ ​ Refrigerated (preferred)​ 28 days​
Ambient ​ 72 hours
Frozen ​ 28 days​
Rejection Criteria

​All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. 

Interference

​Consumption of seafood before collection of a urine specimen for arsenic testing is likely to result in a report of an elevated concentration of arsenic found in the urine, which can be clinically misleading.

Performing Laboratory Information
Performing Location Day(s) Test Performed Report Available Methodology/Instrumentation
Mayo Clinic Laboratories
Monday through Saturday​
1 to 4 days
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)​
Reference Lab
Reference Range Information

0-17 years:  not established

> or = 18 years:  <35 mcg/24 hour

Interpretation

Physiologically, arsenic exists in a number of toxic and nontoxic forms. The total arsenic concentration reflects all the arsenic present in the sample regardless of species (eg, inorganic vs. methylated vs. organic arsenic). The measurement of urinary total arsenic levels is generally accepted as the most reliable indicator of recent arsenic exposure. However, if the total urine arsenic concentration is elevated, arsenic speciation must be performed to identify if it is the toxic forms (eg, inorganic and methylated forms) or the relatively non-toxic organic forms (eg, arsenobetaine and arsenocholine).

The inorganic toxic forms of arsenic (eg, As[III] and As[V]) are found in the urine shortly after ingestion, whereas the less toxic methylated forms (monomethylarsinic acid: MMA dimethylarsinic acid: DMA) are the species that predominate longer than 24 hours after ingestion. In general, urinary As(III) and As(V) concentrations peak in the urine at approximately 10 hours and return to normal 20 to 30 hours after ingestion. Urinary MMA and DMA concentrations normally peak at approximately 40 to 60 hours and return to baseline 6 to 20 days after ingestion.

After a seafood meal (seafood generally contains the nontoxic, organic form of arsenic (eg, arsenobetaine), the urine output of arsenic may increase to over 300 mcg/24 hour specimen, after which it will decline. 

This test can determine if you have been exposed to above-average levels of arsenic. It cannot predict whether the arsenic levels in your body will affect your health.

Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​82175 ​1
​82175​1​if needed
Synonyms/Keywords
Arsenic (As), As (Arsenic)
Test Components

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

Ordering Applications
Ordering Application Description
​Centricity ​Arsenic, 24 Hr Urine (8644)
​Cerner ​Arsenic Level 24 Hour Urine (8644)
​COM ​Arsenic, 24 Hr Urine
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
Urine​ Clean, plastic urine container with no metal cap or glued insert​ 10 mL​ 3 mL​
Collection Processing
​Submit sample in a plastic, 10-mL urine tube or clean, plastic aliquot container with no metal cap or glued insert.
1. Collect urine for 24 hours.
2. Refrigerate specimen within 4 hours of completion of 24-hour collection.
Additional Information:
1. 24-Hour volume is required.
2. 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.
3. Patient should not eat seafood for a 48-hour period prior to start of collection. 
Specimen Stability Information
Specimen Type Temperature Time
Urine​ ​ ​ Refrigerated (preferred)​ 28 days​
Ambient ​ 72 hours
Frozen ​ 28 days​
Rejection Criteria

​All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. 

Interference

​Consumption of seafood before collection of a urine specimen for arsenic testing is likely to result in a report of an elevated concentration of arsenic found in the urine, which can be clinically misleading.

Useful For
​Preferred screening test for detection of arsenic exposure using 24-hour urine specimens
Test Components

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

Reference Range Information

0-17 years:  not established

> or = 18 years:  <35 mcg/24 hour

Interpretation

Physiologically, arsenic exists in a number of toxic and nontoxic forms. The total arsenic concentration reflects all the arsenic present in the sample regardless of species (eg, inorganic vs. methylated vs. organic arsenic). The measurement of urinary total arsenic levels is generally accepted as the most reliable indicator of recent arsenic exposure. However, if the total urine arsenic concentration is elevated, arsenic speciation must be performed to identify if it is the toxic forms (eg, inorganic and methylated forms) or the relatively non-toxic organic forms (eg, arsenobetaine and arsenocholine).

The inorganic toxic forms of arsenic (eg, As[III] and As[V]) are found in the urine shortly after ingestion, whereas the less toxic methylated forms (monomethylarsinic acid: MMA dimethylarsinic acid: DMA) are the species that predominate longer than 24 hours after ingestion. In general, urinary As(III) and As(V) concentrations peak in the urine at approximately 10 hours and return to normal 20 to 30 hours after ingestion. Urinary MMA and DMA concentrations normally peak at approximately 40 to 60 hours and return to baseline 6 to 20 days after ingestion.

After a seafood meal (seafood generally contains the nontoxic, organic form of arsenic (eg, arsenobetaine), the urine output of arsenic may increase to over 300 mcg/24 hour specimen, after which it will decline. 

This test can determine if you have been exposed to above-average levels of arsenic. It cannot predict whether the arsenic levels in your body will affect your health.

For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Report Available Methodology/Instrumentation
Mayo Clinic Laboratories
Monday through Saturday​
1 to 4 days
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)​
Reference Lab
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​82175 ​1
​82175​1​if needed
For most current information refer to the Marshfield Laboratory online reference manual.