ARUP's Laboratory Test Directory

Arsenic, Urine with Reflex to Fractionated : 0025000

Mnemonic: ARS U

Methodology: Quantitative High Performance Liquid Chromatography/Quantitative Inductively Coupled Plasma-Mass Spectrometry
Performed: Mon-Fri
Reported: 1-5 days
Specimen Required: Patient Prep: Diet, medication, and nutritional supplements may introduce interfering substances. Patients should be encouraged to discontinue nutritional supplements, vitamins, minerals, nonessential 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.

Collect: 24-hour or random urine collection. Specimen must be collected in a plastic container and 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 an 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.

Stability (collection to initiation of testing): Ambient: 1 week; Refrigerated: 2 weeks; Frozen: 1 year
Reference Interval:

 
Test Number Components Reference Interval
 Arsenic, Urine0-35.0 µg/L (based on Biological Exposure Index)
 Arsenic, Urine (24-hour)0-50.0 µg/d
 Arsenic per gram of creatinineNo reference interval (µg/g crt)
0020734Arsenic, Fractionated, Urine  
 
Test Number Components Reference Interval
 As Organic Refer to report
 Arsenic Total Inorganic Refer to report
 Arsenic, Methylated Refer to report
 Creatinine, Urine - per 24h  
 
Age Male Female
3-8 years 140-700 mg/d 140-700 mg/d
9-12 years 300-1300 mg/d 300-1300 mg/d
13-17 years 500-2300 mg/d 400-1600 mg/d
18-50 years 1000-2500 mg/d 700-1600 mg/d
51-80 years 800-2100 mg/d 500-1400 mg/d
81 years and older 600-2000 mg/d 400-1300 mg/d

Interpretive Data: 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.
Note: If total arsenic concentration is between 35-2000 ug/L, then Arsenic, Fractionated, will be added to determine the proportion of organic, inorganic, and methylated forms. Additional charges apply.
CPT Code(s): 82175; if reflexed, add 82175 
Cross References: Arsenic/Creatinine Ratio, Random, Urine (Arsenic, Urine with Reflex to Fractionated), As (Arsenic, Urine with Reflex to Fractionated), ASU (Arsenic, Urine with Reflex to Fractionated)