Heavy Metals Screen, with Reflex, 24 Hour, Urine
Use
Detecting arsenic, cadmium, mercury, and lead exposure and toxicity using 24‑hour urine specimens. The test provides quantification of total arsenic, cadmium, mercury, and lead, with reflex speciation of arsenic if concentration is ≥10 µg/L, to discriminate toxic inorganic or methylated species from nontoxic organic forms.
Special Instructions
Reflex testing: If arsenic concentration ≥ 10 mcg/L, then arsenic speciation (SPASU) is performed at additional charge. Special instructions include using 24‑hour urine, proper preservative/temperature management within 4 hours of collection, and avoidance of seafood consumption and recent gadolinium/iodine contrast administration (no collection within 96 hours after).
Limitations
Total arsenic elevation may be misleading after seafood ingestion due to organic arsenic, necessitating speciation to clarify toxic exposure. Urinary lead reflects recent exposure and exhibits high intra‑individual variability. Cadmium reflects long‑term exposure but is influenced by creatinine; interpretation must consider body burden context. All specimens are evaluated at the lab for suitability.
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 94575-8
- 5612-7
- 13362-9
- 3167-4
- 21074-0
- 5587-1
- 6693-6
- 5677-0
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
6 mL aliquot
Minimum Volume
3 mL
Container
Clean, plastic aliquot container with no metal cap or glued insert; submission in 10 mL plastic urine tube (Supply T068)
Collection Instructions
Collect urine for 24 hours; refrigerate within 4 hours of completion; avoid seafood 48 h prior and during collection; wait 96 h after gadolinium or iodine contrast before collection.
Patient Preparation
Do not eat seafood for the 48 hours prior to and during collection; avoid collection within 96 hours after gadolinium‑ or iodine‑based contrast media.
Causes for Rejection
Unsuitable specimen conditions; evaluation by lab for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |
| Frozen | 7 days |