Test Overview

Test Methodology

Liquid Chromatography with Tandem Mass Spectrometry (LC/MS-MS)

Test Usage

Monitoring possible exposure to cyanide; establishing cause of death in cyanide exposure.

Reference Range*

Normal: Up to 0.05 mcg/mL
Potentially toxic: 0.50 mcg/mL and greater
Potentially lethal: 2.0 mcg/mL and greater

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

Not useful for monitoring nitroprusside therapy; the Thiocyanante assay is the preferred test for monitoring nitroprusside therapy.

Test Details

Days Test Performed


Analytic Time

7 - 11 days

Soft Order Code


MiChart Code

Cyanide Level




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Laboratory Reference

Mayo FCYNB (NMS 1380B)

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Specimen Requirements

Offsite Collection Instructions

Collect blood in a gray top tube. Send intact whole blood FROZEN.

Normal Volume

2 mL whole blood

Minimum Volume

0.5 mL whole blood

Additional Information

Test sent to Mayo Medical Laboratories; performed by NMS Labs.

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