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Test Code KETAX Ketamine and Metabolite Confirmation, Chain of Custody, Urine

Useful For

Detection and confirmation of ketamine use


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

Ketamine Confirmation, CoC, U

Specimen Type


Specimen Required

Container/Tube: Chain-of-Custody Kit (T282) containing the specimen containers, seals, and documentation required.

Specimen Volume: 20 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

1. No specimen substitutions.

2. No STATS are accepted for this procedure.

3. Submitting less than 20 mL will compromise our ability to perform all necessary testing.

Specimen Minimum Volume

5 mL

Specimen Stability Information

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

Reject Due To









Clinical Information

Ketamine has been used in the United States as an anesthetic induction agent since 1972. The drug acts by noncompetitive antagonism of the N-methyl-D-aspartate (NMDA)-type glutamate receptors.(1,2) Ketamine has become a popular street drug because of its hallucinogenic effects.(3)


Ketamine has a half-life of 3 to 4 hours, and is metabolized to norketamine.(3) The effects from ketamine last from 1 to 5 hours, and ketamine and/or norketamine can be detected in the urine for a period of 1 to 2 days following use.(4)


Chain of custody is a record of the disposition of a specimen to document who collected it, who handled it, and who 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



The presence of ketamine and/or norketamine >25 ng/mL is a strong indicator that the patient has used ketamine.


No significant cautionary statements

Method Description

Phencyclidine, norketamine, and ketamine, along with the deuterated internal standards, are extracted from buffered urine using solid-phase extraction techniques. The eluent from the column is dried and then analyzed by gas chromatography-mass spectrometry.(Unpublished Mayo method)

Day(s) and Time(s) Performed


Analytic Time

2 days

Specimen Retention Time

2 weeks

Performing Laboratory

Mayo Medical 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 U.S. Food and Drug Administration.

CPT Code Information


G0480 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
KETAX Ketamine Confirmation, CoC, U In Process


Result ID Test Result Name Result LOINC Value
36194 Norketamine 72799-0
36195 Ketamine Confirmation 20537-7
36196 Ketamine Interpretation 69050-3
36197 Chain of Custody 77202-0

Method Name

Gas Chromatography-Mass Spectrometry (GC-MS)


Chain-of-Custody Request Form is included in the Chain-of-Custody Kit (T282). A copy of this form is also available at