- 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) Record total volume and collection time interval on transport tube and on test request form.
- 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.
- Ambient: 1 week; Refrigerated: 2 weeks; Frozen: 1 year
|Test Number||Components||Reference Interval|
|Arsenic, Urine||0-35.0 µg/L (based on Biological Exposure Index)|
|Arsenic, Urine (24-hour)||0-50.0 µg/d|
|Arsenic per gram of creatinine||No reference interval (µg/g crt)|
|0020734||Arsenic, Fractionated, Urine|| |
|Lead, Urine||0-23 µg/L|
|Lead, Urine (24-hour)||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|| |
|0025040||Cadmium, Urine|| |
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 for the sum of inorganic and methylated forms (species) of arsenic is 35 µg/L. For specimens with a total arsenic concentration between 35-2000 µg/L, fractionation is performed to determine the proportion of the inorganic, methylated, and organic forms. Inorganic forms of arsenic are most toxic. Methylated forms arise primarily from metabolism of inorganic forms but may also come from dietary sources and are of moderate toxic potential. The organic forms of arsenic are considered nontoxic and arise primarily from food. The sum of the inorganic, methylated, and organic forms of arsenic may be lower than the total arsenic level.
If low-level chronic poisoning is suspected, the µg/gCRT ratio may be more sensitive than the total arsenic concentration. It may be appropriate to fractionate specimens with a µg/gCRT ratio greater than 30 despite a total arsenic concentration less than 35 µg/L. Performed upon request.
|Component Test Code*||Component Chart Name|
|0020207||Creatinine, Urine - per volume|
|0020208||Creatinine, Urine - per 24h|
|0025001||Arsenic Urine - per volume|
|0025002||Arsenic Urine - per 24h|
|0025038||Cadmium, Urine - ratio to CRT|
|0025041||Cadmium, Urine - per 24h|
|0025042||Cadmium, Urine - per volume|
|0025051||Mercury, Urine - per 24h|
|0025052||Mercury, Urine - per volume|
|0025054||Mercury, Urine - ratio to CRT|
|0025058||Arsenic, Urine - ratio to CRT|
|0025061||Lead, Urine - per 24h|
|0025062||Lead, Urine - per volume|
|0025065||Lead, Urine - ratio to CRT|
- Arsenic (As)
- Cadmium (Cd)
- Lead (Pb)
- Mercury (Hg)
- Metals Screen
- Toxicology Quantitative Screen, Metals