Sign in →

Test ID: BARBU Barbiturates Confirmation, Random, Urine

Reporting Name

Barbiturates Confirmation, U

Useful For

Detecting drug abuse involving barbiturates such as amobarbital, butalbital, pentobarbital, phenobarbital, and secobarbital

Specimen Type


Ordering Guidance

1. For situations where chain of custody is required, a Chain-of-Custody Kit (T282) is available. For chain-of-custody testing, order BARBX / Barbiturates Confirmation, Chain of Custody, Random, Urine.

2. Additional drug panels and specific requests are available. Call 800-533-1710 or 507-266-5700.

3. If urine creatinine is required or adulteration of the sample is suspected, order ADULT / Adulterants Survey, Random, Urine.

Specimen Required

Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic, 10-mL urine tube

Specimen Volume: 10 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.

Additional Information:

1. No specimen substitutions.

2. STATS are not accepted for this test.

Specimen Minimum Volume

5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 14 days
  Frozen  14 days
  Ambient  72 hours

Reference Values



Cutoff concentrations:


<100 ng/mL



<100 ng/mL



<100 ng/mL



<100 ng/mL



<100 ng/mL

Day(s) Performed

Tuesday, Thursday, Sunday

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


G0480 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BARBU Barbiturates Confirmation, U 53746-4


Result ID Test Result Name Result LOINC Value
21442 Butalbital-by GC/MS 16237-0
20642 Amobarbital-by GC/MS 16239-6
20643 Pentobarbital-by GC/MS 16240-4
20644 Secobarbital-by GC/MS 16238-8
20645 Phenobarbital-by GC/MS 16241-2
20651 Barbiturates Interpretation 69050-3
20647 Chain of Custody 77202-0

Clinical Information

Barbiturates represent a class of drugs that were originally introduced as sleep inducers. Butalbital is also used to control severe headaches. Mephobarbital and phenobarbital are frequently used to control major motor (grand mal) seizures. These drugs are commonly abused as "downers" to induce sleep after an amphetamine- or cocaine-induced "high."


The presence of a barbiturate in urine indicates use of one of these drugs.


Most of the barbiturates are fast acting; their presence indicates use within the past 3 days.


Phenobarbital, commonly used to control epilepsy, has a very long half-life. The presence of phenobarbital in urine indicates that the patient has used the drug sometime within the past 30 days.

Clinical Reference

1. Disposition of Toxic Drugs and Chemicals in Man. 10th edition. Edited by RC Baselt. Foster City, CA: Biomedical Publications, 2014

2. Langman LJ et al: Clinical Toxicology. In Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Edited by N Rifai, AR Horvath, CT Wittwer. Sixth edition. Elsevier, 2018, pp 832-887

Report Available

3 to 5 days

Method Name

Gas Chromatography-Mass Spectrometry (GC-MS) Confirmation with Quantitation


If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen. 

Mayo Clinic Laboratories | Therapeutics Catalog Additional Information:

mml-barbiturates, mml-substancemonitoring