Reference Interval:
| Test Number
| Components
| Reference Interval
| | | As Organic
| By report
| | | Arsenic Total Inorganic
| By report
| | | Arsenic, Methylated
| By report
|
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| Interpretive Data: |
Specific toxic thresholds for arsenic are not well defined. The ACGIH Biological Exposure Index is 35 µg/L for the sum of the inorganic and methylated forms of arsenic. For specimens with a total arsenic concentration between 35-2000 µg/L, fractionation is performed to determine the proportion of organic, inorganic, and methylated forms. 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 µg/gCRT despite a total arsenic concentration less than 35 µg/L. The laboratory will perform this fractionation on request.
The organic forms of arsenic, most commonly arsenobetaine, are considered nontoxic and arise primarily from food. Inorganic forms of arsenic As(III) and As(V)] are most toxic. Methylated forms (MMA and DMA) arise primarily from metabolism of inorganic forms but may also come from dietary sources and are of moderate toxic potential. As this test does not detect all species of arsenic, it is expected that the sum of the organic, inorganic, and methylated forms will not equal the total arsenic concentration.
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| CPT Code(s): |
82175
|
Cross References: |
ASFR (Arsenic, Fractionated, Urine) |
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