ICP/MS Trace Mineral/Toxic Metal Screen Sample Submission Guidelines and Best Practices

The Toxicology Section offers trace mineral and toxic metal panels to diagnose trace nutrient deficiencies or heavy metal toxicoses in animals. These screens cover a variety of analytes in biological samples from animals (postmortem and antemortem), and environmental samples. The results of these screens may be influenced by the quality, quantity, or integrity of the sample. This sample submission guideline describes best practices to optimize trace mineral and toxic metal screen results and diagnostic interpretation. Pertinent information regarding preferred specimens to submit for each test, including sample storage and shipping, is included below.

Bone Screen

• Preferred Sample
  • Bovine - Rib bone
  • Avian, Caprine, Ovine, Porcine - Femur
  • Equine - Metacarpal bone
• Store refrigerated until submission and ship chilled.

Trace Mineral/Toxic Metal Screen in Blood

• Minimum Sample Volume:
  • 1 mL
• Collect whole blood in a test tube containing an anticoagulant such as EDTA or heparin.
• Store refrigerated until submission and ship chilled.

Trace Mineral Screen in Plasma/Serum

• Minimum Sample Volume:
  • 1 mL
• Collect whole blood in a red top (clot) tube or in a test tube containing an anticoagulant, such as EDTA or heparin.
  • If submitting a whole blood sample in a red top (clot) tube not containing an anticoagulant for this test, store the whole blood refrigerated until submission and ship cold; do not freeze the sample. Freezing whole blood can result in hemolyzed plasma/serum.
    • Hemolysis can artificially increase calcium, iron, magnesium, selenium, and zinc in the plasma/serum sample and potentially decrease sodium. ^1-2
    • More information on best practices to prevent hemolysis of plasma/serum samples can be found here: Hemolysis in Blood Specimens.
  • NOTE: Rubber stoppers in commercially available test tubes or vacutainer tubes contain zinc, which can leach into the diagnostic samples. Care should be taken to avoid prolonged contact between the sample and the rubber stopper, as this can artificially increase the zinc concentration in the plasma/serum.
• Refrigerate the whole blood until submission and ship chilled. Store the plasma/serum refrigerated or frozen and ship chilled.

Trace Mineral/Toxic Metal Screen in Tissue (Liver/Kidney)

• Minimum Sample Weight:
  • 1 gram (post-mortem) or 0.05 grams (ante-mortem biopsy samples)
• Avoid submitting formalin-fixed tissue. Cadmium, copper, iron, manganese, and selenium have been shown to leach out of tissue after formalin fixation. ^4-6 This can result in artificially decreased concentrations of these trace minerals in the diagnostic sample.
• Depending on the type of biopsy needle used, multiple biopsies may need to be performed to obtain the minimum weight.
  • If using a Stryker double-action biopsy clamp (5 mm diameter) or a Quick Core^® biopsy needle (10 -20 mm throw length), a biopsy sample of approximately 0.1 to 0.2 grams can be obtained and therefore, only one biopsy is needed.
  • If using a Tru-Cut^® biopsy needle (14 G), the maximum biopsy size obtained will be approximately 0.025 grams. Therefore, approximately 3 biopsies may be warranted to meet the minimum sample weight.
  • Liver biopsies should be collected into a sterile container (e.g., red top clot tube) without any saline or other preservative.
• Fresh tissue or biopsies should be stored refrigerated or frozen and shipped chilled.

Trace Mineral Screen in Water

• Minimum Sample Volume:
  • 1 Liter
• Collect a representative sample of water in a non-metal, sealed container. If submitting water samples for the trace mineral screen and the water quality screen, a minimum sample volume of 2 liters is preferred.
• Store water sample refrigerated until submission and ship chilled.

View a complete list of the trace mineral/toxic metal screens and the analytes covered in each screen.

References

1. Killilea et al., 2021. Identification of a hemolysis threshold that increases plasma and serum zinc concentration. Nutrition, 147(6): 1218-1225.
2. Larran et al., 2018. Influence of hemolysis on the mineral profile in cattle serum. Animals, 11(12): 3336.
3. McCormack et al., 2020. Effects of formalin fixation on trace element concentrations in bottlenose dolphin (Turisops truncates) tissues. Environ Toxicol Chem, 39(6): 1149-1164.
4. Bischoff et al., 2008. The effects of formalin fixation and tissue embedding of bovine liver on copper, iron, and zinc analysis. J Vet Diag Invest, 20: 220-224.
5. Gellein et al., 2008. Leaching of trace elements from biological tissue by formalin fixation. Biol Trace Elem Res, 121:221–225.