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HelpTest Code VLTBX Volatile Screen, Chain of Custody, Blood
Useful For
Detection and quantitation of acetone, methanol, isopropanol, and ethanol in whole blood
Quantification of the concentration of ethanol in blood that correlates with the degree of intoxication
Evaluation of toxicity to the measured volatile substances
This test is not intended for use in employment-related testing.
Providing chain-of-custody for when the results of testing could be used in a court of law. Its purpose is to protect the rights of the individual contributing the specimen by demonstrating that it was always under the control of personnel involved with testing the specimen; this control implies that the opportunity for specimen tampering would be limited.
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.
Reporting Name
Volatile Screen, CoC, BSpecimen 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 | Special Container |
|---|---|---|---|
| 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
Interpretation
Methanol:
The presence of methanol indicates exposure that may result in intoxication, central nervous system (CNS) depression, and metabolic acidosis. Ingestion of methanol can be fatal if patients do not receive immediate medical treatment.
Ethanol:
The presence of ethanol indicates exposure that may result in intoxication, CNS depression, and metabolic acidosis.
Isopropanol:
The presence of isopropanol indicates exposure that may result in intoxication and CNS depression. Ingestion of isopropanol can be fatal if patients do not receive immediate medical treatment.
Acetone:
The presence of acetone may indicate exposure to acetone; it is also a metabolite of isopropanol and may be detected during ketoacidosis.
Cautions
This test does not detect ethylene glycol.
Clinical Reference
1. Langman LJ, Bechtel LK, Holstege CP. Clinical toxicology. In: Rifai N, Chiu RWK, Young I, Burnham CD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 43
2. Mayfield J, Mihic SJ. Ethanol. In: Brunton LL, Knollmann BC. Goodman and Gilman's: The Pharmacological Basis of Therapeutics. 13th ed. McGraw-Hill Education; 2022:chap 27
3. Olson KR, Anderson IB, Benowitz NL, et al. Specific Poisons and Drugs: Diagnosis and Treatment. In: Poisoning and Drug Overdose. 8th ed. McGraw-Hill; 2022:section II
Method Description
Samples are analyzed and quantified by headspace gas chromatography with flame ionization detection.(Baselt RC. Disposition of Toxic Drugs and Chemicals in Man. 10th ed. Biomedical Publications; 2014:2211)
Day(s) Performed
Monday through Saturday
Report Available
1 to 2 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80320
G0480 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| VLTBX | Volatile Screen, CoC, B | 41266-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 36241 | Volatile Scrn, B | 41266-8 |
| 36242 | Methanol, B | 9334-4 |
| 36243 | Ethanol, B | 5640-8 |
| 36244 | Acetone, B | 9425-0 |
| 36245 | Isopropanol, B | 5667-1 |
| 36246 | Chain of Custody | 77202-0 |
Method Name
Headspace Gas Chromatography Flame Ionization Detector (HSGC-FID)
Secondary ID
62745Forms
Chain of Custody Request is included in the Chain-of-Custody Kit (T282)