Sign in →

Arsenic Fractionation, Random, Urine

Reporting Name

Arsenic Fractionation, Random, U
Seattle Children's Hospital Note:

Clinical System Name: Miscellaneous Test

Useful For

Diagnosis of arsenic intoxication

Specimen Required

Patient Preparation:

1. Patient should not eat seafood for a 48-hour period prior to start of collection.

2. 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.

Supplies: Aliquot Tube, 5 mL (T465)

Collection Container/Tube: Clean, plastic urine collection container

Submission Container/Tube: Plastic, 5-mL tube (T465) or a clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen.

2. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

Specimen Type


Specimen Minimum Volume

5 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 7 days
  Ambient  7 days
  Frozen  7 days

Day(s) and Time(s) Performed

Monday through Friday; 8 a.m.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Method Name

Liquid-Liquid Extraction/Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Method Description

Inorganic arsenic, monomethylarsonic acid (MMA), and cacodylic acid (dimethyl arsinic acid, [DMA]) in urine correlate with nondietary (toxic) exposure to arsenic, while arsenobetaine and arsenocholine in urine represent dietary (seafood) exposure and are of little or no significance. Arsenic acid, arsonic acid, MMA, and DMA are reduced and complexed in the presence of strong hydrochloric acid and potassium iodide and the resulting compounds extracted with toluene as iodine complexes, while nontoxic, organic arsenobetaine and arsenocholine remain in the organic fraction and are discarded. Arsenic in the extract is determined by inductively coupled plasma-mass spectrometry (ICP-MS) according to the standard operating procedure for urine total arsenic determinations.(Nixon DE, Moyer TP: Routine clinical determination of lead, arsenic, cadmium, and thallium in urine and whole blood by inductively coupled plasma mass spectrometry. Spectrochimica Acta B 1996;51:13-25)

Reference Values


0-24 mcg/L 

Reference values apply to all ages.

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
ASFRU Arsenic Fractionation, Random, U 54454-4


Result ID Test Result Name Result LOINC Value
32311 Inorganic Arsenic (Toxic) 12481-8
32312 Organic Arsenic (Non-Toxic) 53778-7

Reject Due To