THC Metabolite, Serum or Plasma, Quantitative
Ordering Recommendation
Detect exposure to cannabinoids.
Quantitative Liquid Chromatography-Tandem Mass Spectrometry
1-4 days  
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
Patient Preparation
Gray (sodium fluoride/potassium oxalate). Also acceptable: Plain red, green (sodium heparin), lavender (EDTA), or pink (K2EDTA).  
Specimen Preparation
Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL)  
Storage/Transport Temperature
Unacceptable Conditions
Separator tubes. Plasma or whole blood collected in lt. blue (sodium citrate). Specimens exposed to repeated freeze/thaw cycles.  
After separation from cells: Ambient: 1 week; Refrigerated: 2 weeks; Frozen: 3 years  
Reference Interval
Effective August 17, 2015
Drugs Covered Cutoff Concentrations
11-​Nor-​9-​carboxy-​THC 5 ng/mL
Interpretive Data
Methodology: Quantitative Liquid Chromatography-Tandem Mass Spectrometry

Positive cutoff:
5 ng/mL

For medical purposes only; not valid for forensic use.

The drug analyte detected in this assay, 9-carboxy THC, is a metabolite of delta-9-tetrahydrocannabinol (THC). Detection of 9-carboxy THC suggests use of, or exposure to, a product containing THC. This test cannot distinguish between prescribed or non-prescribed forms of THC, nor can it distinguish between active or passive use. The plasma half-life for 9-carboxy THC metabolite is estimated to range from 4-12 hours.

Compliance Statement B: This test was developed and its performance characteristics determined by ARUP Laboratories. The U.S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.
CPT Code(s)
80349; (Alt code: 82491)
Component Test Code*Component Chart NameLOINC
009067111-Nor-9-carboxy-THC, S/P, Quant8170-3
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • 9-Carboxy-THC
  • Cannabinoids
  • Cannabis
  • Dronabinol
  • Marijuana
  • Marinol
  • Pain Management
  • THC