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Test Code BARBX Barbiturates Confirmation, Chain of Custody, Random, Urine

Useful For

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


Chain of custody is required whenever 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 under the control of personnel involved with testing the specimen at all times; 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
ADLTX Adulterants Survey, CoC, U Yes Yes

Testing Algorithm

Adulterants testing will be performed on all chain-of-custody urine samples as per regulatory requirements.

Reporting Name

Barbiturates Confirmation, CoC, U

Specimen Type


Specimen Required

Supplies: Chain of Custody Kit (T282)

Container/Tube: Chain of custody kit (T282) containing the specimen containers, seals, and documentation required

Specimen Volume: 10 mL

Collection Instructions: Collect specimen in the container provided, seal, and submit with the associated documentation to satisfy the legal requirements for chain-of-custody testing.

Additional Information: Submitting <10 mL will compromise our ability to perform all necessary testing.

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:



<200 ng/mL



Butalbital: <100 ng/mL

Amobarbital <100 ng/mL

Pentobarbital <100 ng/mL

Secobarbital <100 ng/mL

Phenobarbital <100 ng/mL

Day(s) Performed

Tuesday, Thursday, Sunday

Report Available

3 to 5 days

Performing 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. 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
BARBX Barbiturates Confirmation, CoC, U 53746-4


Result ID Test Result Name Result LOINC Value
6668 Barbiturates Immunoassay Screen 70155-7
36143 Butalbital-by GC/MS 16237-0
36144 Amobarbital-by GC/MS 16239-6
36145 Pentobarbital-by GC/MS 16240-4
36146 Secobarbital-by GC/MS 16238-8
36147 Phenobarbital-by GC/MS 16241-2
36148 Barbiturates Interpretation 69050-3
36149 Chain of Custody 77202-0

Method Name

BARBX: Immunoassay/Gas Chromatography-Mass Spectrometry (GC-MS) Confirmation with Quantitation

ADLTX: Spectrophotometry (SP)


1. Chain of Custody Request is included in the Chain of Custody Kit (T282).

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