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HelpTest Code VLTBX Volatile Screen, Chain of Custody, Blood
Additional Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| COCH | Chain of Custody Processing | No | Yes |
Testing Algorithm
This test includes analysis of methanol, ethanol, isopropanol, and acetone.
Specimen Type
Whole bloodSpecimen Required
Supplies: Chain-of-Custody Kit (T282)
Container/Tube: Chain-of-Custody Kit containing the specimen container seals and documentation required.
Preferred: Gray top (potassium oxalate/sodium fluoride)
Acceptable: Lavender top (EDTA) or green top (sodium heparin)
Specimen Volume: 2 mL
Collection Instructions:
1. Do not use alcohol to clean arm. Use alternative such as Betadine to cleanse arm before collecting any specimen for volatile testing.
2. Specimen must be sent in original tube. Collect specimen, seal, and submit with the associated documentation to satisfy the legal requirements for chain of custody testing.
Specimen Minimum Volume
0.5 mL or amount to fill 1 tube
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole blood | Refrigerated (preferred) | 14 days |
| Frozen | 28 days | |
| Ambient | 24 hours |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | Reject |
| Gross icterus | OK |
Clinical Information
Volatile substances in the blood include ethanol, methanol, isopropanol, and acetone. Acetone is generally elevated in metabolic conditions such as diabetic ketoacidosis. Methanol and isopropanol are highly toxic and result from exogenous ingestion.
Ethanol is one of the most widely abused legal substances in the United States. It is the active agent in beer, wine, vodka, whiskey, rum, and other liquors. Ethanol acts on cerebral function as a depressant similar to general anesthetics. This depression causes most of the typical symptoms such as impaired thought, clouded judgment, and changed behavior. As the level of alcohol increases, the degree of impairment progressively increases.
In most jurisdictions in the United States, the per se blood level for being under the influence of alcohol (ethanol) for purposes of driving a motor vehicle is 80 mg/dL (0.08%).
Chain of custody is required whenever the results of testing could be used in a court of law. Chain of custody is a record of the disposition of a specimen to document the individuals that collected it, handled it, and performed the analysis. When a specimen is submitted in this manner, analysis will be performed in such a way that it will withstand regular court scrutiny.
Reference Values
Methanol:
Not detected (Positive results are quantitated.)
Toxic concentration: ≥10 mg/dL
Ethanol:
Not detected (Positive results are quantitated.)
Toxic concentration: ≥400 mg/dL
Isopropanol:
Not detected (Positive results are quantitated.)
Toxic concentration: ≥10 mg/dL
Acetone:
Not detected (Positive results are quantitated.)
Toxic concentration: ≥10 mg/dL
Day(s) Performed
Monday through Saturday
Report Available
1 to 2 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
80320
G0480 (if appropriate)
Method Name
Headspace Gas Chromatography Flame Ionization Detector (HSGC-FID)
Forms
Chain of Custody Request is included in the Chain-of-Custody Kit (T282)