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23079 Thallium, 24 Hour, Urine (TLU)

Thallium, 24 Hour, Urine (TLU)
Test Code: MISC
Synonyms/Keywords
​Tl (Thallium)
Useful For
Detecting toxic thallium exposure in 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 0.3 mL​
Collection Processing Instructions
1. Collect urine for 24 hours.
2. No preservative.
3. See Metals Analysis-Collection and Transport in Special Instructions for complete instructions.
Trace Metals Analysis - Specimen Collection and Transport
4. Refrigerate specimen within 4 hours of completion of 24-hour collection.
5. Submit specimen in plastic, 10-mL urine tube or a clean, plastic aliquot container with no metal cap or glued insert
Additional Information:
1. 24-Hour volume is required.
2. See Urine Preservatives in Special Instructions for multiple collections.
Urine Preservative Cross-Reference Information
3. 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.
Specimen Stability Information
Specimen Type Temperature Time
Urine​ ​Refrigerated (preferred) 28 days
​Ambient ​28 days
​Frozen ​28 days
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories Tuesday, Friday ​1 day
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)​
Reference Lab
Test Information
Thallium is odorless and tasteless and is found in trace amounts in the earth's crust. It is used in the manufacturing of electronic devices, switches, and closures. It had previously been used in rodenticides. The greatest exposure can occur from eating food (eg fruits and vegetables) since its easily taken up by plants through the roots. Cigarette smoking is also a source of exposure. Accidental ingestion may lead to vomiting, diarrhea, and leg pains followed by a severe and sometimes fatal sensorimotor polyneuropathy. Alopecia (hair loss) may occur 3 weeks after poisoning. The fatal dose is approximately 1 gram. Most thallium is excreted in the urine and can be found within an hour after exposure and be detected as long as two months after exposure.
Reference Range Information
0-17 years:  not established
> or = 18 years:  <2 mcg/24 hour 
Interpretation
Patients exposed to high doses of thallium (>1 g) present with alopecia, peripheral neuropathy, seizures, and renal failure.
 
Exposed patients can have urine output >10 mcg/day. The long-term consequences of such an exposure are poor.
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
83018
Synonyms/Keywords
​Tl (Thallium)
Ordering Applications
Ordering Application Description
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 0.3 mL​
Collection Processing
1. Collect urine for 24 hours.
2. No preservative.
3. See Metals Analysis-Collection and Transport in Special Instructions for complete instructions.
Trace Metals Analysis - Specimen Collection and Transport
4. Refrigerate specimen within 4 hours of completion of 24-hour collection.
5. Submit specimen in plastic, 10-mL urine tube or a clean, plastic aliquot container with no metal cap or glued insert
Additional Information:
1. 24-Hour volume is required.
2. See Urine Preservatives in Special Instructions for multiple collections.
Urine Preservative Cross-Reference Information
3. 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.
Specimen Stability Information
Specimen Type Temperature Time
Urine​ ​Refrigerated (preferred) 28 days
​Ambient ​28 days
​Frozen ​28 days
Useful For
Detecting toxic thallium exposure in 24-hour urine specimens ​
Reference Range Information
0-17 years:  not established
> or = 18 years:  <2 mcg/24 hour 
Interpretation
Patients exposed to high doses of thallium (>1 g) present with alopecia, peripheral neuropathy, seizures, and renal failure.
 
Exposed patients can have urine output >10 mcg/day. The long-term consequences of such an exposure are poor.
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories Tuesday, Friday ​1 day
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)​
Reference Lab
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
83018
For most current information refer to the Marshfield Laboratory online reference manual.