Specimen Collection and Handling
- Patient Preparation
- Diet, medication, and nutritional supplements may introduce interfering substances. Patients should be encouraged to discontinue nutritional supplements, vitamins, minerals, non-essential over-the-counter medications (upon the advice of their physician), and avoid shellfish and seafood for 48 to 72 hours. High concentrations of iodine may interfere with elemental testing. Abstinence from iodine-containing medications or contrast agents for at least 1 month prior to collecting specimens for elemental testing is recommended.
- 24-hour or random urine collection. Specimen must be collected in a plastic container and should be refrigerated during collection. ARUP studies indicate that refrigeration of urine alone, during and after collection, preserves specimens adequately if tested within 14 days of collection.
- Specimen Preparation
- Transfer 8 mL aliquot from a well-mixed collection to ARUP Trace Element-Free Transport Tubes (ARUP supply #43116). Available online through eSupply using ARUP Connect or contact ARUP Client Services at (800) 522-2787. (Min: 2 mL)
- Storage/Transport Temperature
- Refrigerated. Also acceptable: Room temperature or frozen.
- Unacceptable Conditions
- Urine collected within 48 hours after administration of a gadolinium (Gd) containing contrast media (may occur with MRI studies). Acid preserved urine. Specimens contaminated with blood or fecal material. Specimen transported in non-trace element-free transport tube (with the exception of the original device).
- Trace Elements requisition form may be required (ARUP form #32990-Barcode; #32991-No Barcode). Record total volume and collection time interval on transport tube and on test request form.
- Ambient: 1 week; Refrigerated: 2 weeks; Frozen: 1 year
|Test Number||Components||Reference Interval|
| ||Arsenic Urine - per volume||0-35.0 µg/L (based on Biological Exposure Index)|
| ||Arsenic Urine - per 24h||0-50.0 µg/d|
| ||Arsenic, Urine - ratio to CRT||Less than 30 ug/gCRT|
|0020734||Arsenic, Fractionated, Urine|
| ||Lead, Urine - ratio to CRT||Less than 5 ug/gCRT|
| ||Lead, Urine - per 24h||0-23 µg/L|
| ||Lead, Urine - per volume||0-31 µg/d|
| ||Mercury, Urine - per 24h||0-15 µg/d|
| ||Mercury, Urine - per volume||0-10 µg/L|
| ||Mercury, Urine - ratio to CRT||Less than or equal to 35 µg/gCRT|
| ||Creatinine, Urine - per 24h|
Urinary mercury levels predominantly reflect acute or chronic elemental or inorganic mercury exposure. Urine concentrations in unexposed individuals are typically less than 10 µg/L. 24 hour urine concentrations of 30 to 100 µg/L may be associated with subclinical neuropsychiatric symptoms and tremor while concentrations greater than 100 µg/L can be associated with overt neuropsychiatric disturbances and tremors. Urine mercury levels may be useful in monitoring chelation therapy.
The ACGIH Biological Exposure Index (BEI) for arsenic in urine is 35 µg/L. The ACGIH BEI is based on the sum of inorganic and methylated species. For specimens with a total arsenic concentration between 35-2000 µg/L, fractionation is automatically performed to determine the proportions of inorganic, methylated and organic species. It may be appropriate to request fractionation for specimens with a total arsenic greater than 30 µg/gCRT despite a total arsenic concentration less than 35 µg/L. If low-level chronic poisoning is suspected, the µg/gCRT ratio may be a more sensitive indicator of arsenic exposure than the total arsenic concentration.
|Component Test Code*||Component Chart Name||LOINC|
|0020207||Creatinine, Urine - per volume||2161-8|
|0020208||Creatinine, Urine - per 24h||2162-6|
|0025001||Arsenic Urine - per volume||21074-0|
|0025002||Arsenic Urine - per 24h||5587-1|
|0025038||Cadmium, Urine - ratio to CRT||13828-9|
|0025041||Cadmium, Urine - per 24h||5612-7|
|0025042||Cadmium, Urine - per volume||5611-9|
|0025051||Mercury, Urine - per 24h||6693-6|
|0025052||Mercury, Urine - per volume||21383-5|
|0025054||Mercury, Urine - ratio to CRT||26688-2|
|0025058||Arsenic, Urine - ratio to CRT||13824-8|
|0025061||Lead, Urine - per 24h||5677-0|
|0025062||Lead, Urine - per volume||20625-0|
|0025065||Lead, Urine - ratio to CRT||29943-8|
- Arsenic (As)
- Cadmium (Cd)
- Lead (Pb)
- Mercury (Hg)
- Metals Screen
- Toxicology Quantitative Screen, Metals