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HelpTest Code COKEX Cocaine and Metabolite Confirmation, Chain of Custody, Random, Urine
Useful For
Detecting and confirming drug abuse involving cocaine
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 always under the control of personnel involved with testing the specimen; this control implies that the opportunity for specimen tampering would be limited.
This test is not intended for use in employment-related testing.
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
Cocaine and metabolite Conf, CoC, USpecimen Type
UrineOrdering Guidance
This test is for situations that require the chain-of-custody process. For testing not requiring chain of custody, order COKEU / Cocaine and Metabolite Confirmation, Random, Urine.
Specimen Required
Supplies: Chain of Custody Kit (T282)
Container/Tube: Chain of custody kit 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 less than 10 mL will compromise the 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 |
Reject Due To
| All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Clinical Information
Cocaine is a drug of current health concern because of its proliferation among recreational drug abusers.
Freebase and crack increase the potential for major cocaine toxicity. Cocaine use is declining across the nation according to the National Institute of Drug Abuse.
Increasingly, laboratory results are disputed or there are medical/legal overtones. Therefore, physicians are finding an increased need to confirm positive results before informing or confronting the patients.
Chain of custody is a record of the disposition of a specimen to document all personnel who collected, handled, 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
Negative
Positives are reported with a quantitative gas chromatography mass spectrometry result.
Cutoff concentrations:
IMMUNOASSAY SCREEN
<150 ng/mL
Cocaine by GC-MS
<50 ng/mL
Benzoylecgonine by GC-MS
<50 ng/mL
Interpretation
Reports will specifically indicate the presence or absence of cocaine and benzoylecgonine.
The presence of cocaine, or its major metabolite, benzoylecgonine, indicates use within the past 4 days.
Cocaine has a 6-hour half-life, so it will be present in urine for 1 day after last use.
Benzoylecgonine has a half-life of 12 hours, so it will be detected in urine up to 72 hours after last use.
There is no correlation between concentration and pharmacologic or toxic effects.
Cautions
No significant cautionary statements
Clinical Reference
1. Baselt RC. Disposition of Toxic Drugs and Chemical in Man. 12th ed. Biomedical Publications; 2020
2. Langman LJ, Bechtel LK, Holstege CP. Clinical toxicology. In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 43
3. Isenschmid DS. Cocaine. In: Levine BS, Kerrigan S, eds. Principles of Forensic Toxicology. 5th ed. Springer Nature; 2020:371-388
Method Description
Drug classes are initially screened by an immunoassay technique. The cocaine assay is based on the kinetic interaction of microparticles in a solution as measured by changes in light transmission. In the absence of sample drug, soluble drug conjugates bind to antibody-bound microparticles, causing the formation of particle aggregates. As the aggregation reaction proceeds in the absence of sample drug, the absorbance increases. When a urine sample contains the drug in question, this drug competes with the drug derivative conjugate for microparticle-bound antibody. Antibody bound to sample drug is no longer available to promote particle aggregation, and subsequent particle lattice formation is inhibited. The presence of sample drug diminishes the increasing absorbance in proportion to the concentration of drug in the sample. Sample drug content is determined relative to the value obtained for a known cutoff concentration of drug.(Package insert: COC2. Roche Diagnostics; 03/2019)
To accommodate the need to confirm specifically the presence of cocaine in urine, Mayo Clinic Laboratories offers a single test to identify cocaine and its principal metabolite, benzoylecgonine, by using gas chromatography mass spectrometry.(Chinn DM, Crouch DJ, Peat MA, Finkle BS, Jennison TA. Gas chromatography-chemical ionization mass spectrometry of cocaine and its metabolites in biological fluids. J Anal Toxicol. 1980;4[1]:37-42; Rosado T, Gonçalves A, Margalho C, Barroso M, Gallardo E. Rapid analysis of cocaine and metabolites in urine using microextraction in packed sorbent and GC/MS. Anal Bioanal Chem. 2017;409(8):2051-2063. doi:10.1007/s00216-016-0152-2)
Day(s) Performed
Monday through Friday
Report Available
2 to 5 daysSpecimen Retention Time
14 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
80353
G0480 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| COKEX | Cocaine and metabolite Conf, CoC, U | 53747-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 2903 | Cocaine Immunoassay Screen | 42241-0 |
| 36162 | Cocaine-by GC/MS | 20519-5 |
| 36163 | Benzoylecgonine-by GC/MS | 16226-3 |
| 36164 | Cocaine Interpretation | 69050-3 |
| 36165 | Chain of Custody | 77202-0 |
Method Name
Immunoassay/Gas Chromatography Mass Spectrometry (GC-MS)
Forms
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.