Arsenic, Urine, with Reflex to Fractionated

Abbrev Code:UARS   
Order Code:LAB362Order Name:Arsenic Urine with Reflex to Fractionated
Methodology:Inductively coupled plasma/mass spectrometry/High performance liquid chromatography
CPT Codes: 82175 x1, 82175 x1
Turnaround Time:Specimens are sent to reference laboratory Mon-Sat; results are reported in 1-5 days.

For tests developed and validated by ARUP (previously referred to as Compliance Statement B, C or D). This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the U.S. Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

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Urine Collection Procedure

Collection Instructions

Specimen:Urine, 24 hour
Optimal Volume:Submit entire collection; analysis requires 2 mL
Container:3 L plastic jug
Collection Instructions:Specimen 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.
Patient Preparation: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.

Collection of urine specimens from patients receiving iodinated or gadolinium-based contrast media should be avoided for a minimum of 72 hours post-exposure. Collection from patients with impaired kidney function should be avoided for a minimum of 14 days post-contrast media exposure.
Causes for Rejection:Specimen not collected on ice or specimen in contact with metal. Acid preserved urine. Specimens contaminated with blood or fecal material, samples not aliquoted into ARUP metal-free plastic vials.

Processing and Shipping

Specimen Processing:Mix collection well before aliquot is taken. Aliquot 8 mL, 2 mL minimum into 2 ARUP blue top metal free plastic vials. Regular aliquot tubes will be rejected. Record total volume and collection duration on transport tube and request form. Store in refrigerator.
Shipping Instructions:Ship at refrigerated temperature.
Stability:1 week at room temperature, 2 weeks refrigerated; 1 year frozen.
Test Performed at or Referral Lab Lab Sendouts  (ARUP)
Referral Lab number:25000


Reference Range:
Arsenic, Urine (per volume) 0-34.9 µg/L (based on Biological Exposure Index)
Arsenic, Urine (per 24 hour) 0-49.9 ug/L
Arsenic, Urine (Urine-ratio to CRT) Less than 29.9 µg/gCRT

Arsenic, Fractionated Urine:
Arsenic, Organic By report
Arsenic, Inorganic By report
Arsenic, Methylated By report
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 primary 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 of less than 35 µg/L. Performed upon request.
Use:Diagnose acute or chronic arsenic poisoning. Urine is preferred to blood levels for detection of chronic exposure. This test is able to differentiate between toxic inorganic and methylated species as well as benign organic forms. Results are reported as total inorganic , total methylated, and organic arsenic.

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