Cannabinoid (THC) Confirmation, Quantitative, by LCMSMS

Biochemical Test Requisition Specimen Information Billing Information Contact Us CPT Codes Print Page


TURNAROUND TIME:   2 - 3 days
PERFORMED :  Monday through Friday  
TESTING METHODOLOGY: High Performance Liquid Chromatography Triple Quadrupole Mass Spectrometer (LC/MSMS).
  • Collect: The confirmation testing should be performed on an aliquot from the same specimen used for the drug screen.  The specimen should be random urine collected in a sterile cup and transferred to a 10 mL vacuette urine container with no additives or preservatives.
  • Min. Collection: 2.0 mLs in a vacuette urine container
  • Transport: Room Temperature; Store refrigerated if analysis is not done immediately.
  • Stability (From time of Collection): Ambient:  5 days; Refrigerated: 2 weeks; Frozen: 2 months.
  • Unacceptable Conditions: Specimen exposed to repeated freeze/thaw cycles or transferred into a tube or cup containing additives or preservatives.
For a complete list of prescription drugs detected refer to the Clinical Drug Monitoring Information Guide link to Analyte Medication List.
Analyte/ Metabolite Positive Cutoffs for Confirmation Testing:
ng/ mL
Unanticipated negative findings may be the result of noncompliance, timing of specimen collection relative to drug exposure, interindividual variations in pharmacokinetics, testing limitations, and or diluted or adulterated urine.
Drug metabolism or exposure to multiple drugs can lead to detection of multiple analytes in urine.  Pharmaceutical manufacturing impurities can result in low concentrations of an anticipated analyte in the presence of large concentrations of another related analyte.
Specimens for which drugs or drug metabolites are detected by the screen are reflexed to a second specific confirmatory quantitative procedure by LCMSMS (Liquid Chromatography Tandem Mass Spectrometry).  Additional charges will apply.
Interpretive questions should be directed to the laboratory.
Analytic Sensitivity: >99%
Test Limitations: Urine creatinine results less than 20mg/dL may indicate adulterated/diluted urine.  Recollection of urine specimen may be requested and preferably from an early morning clean catch collection. 
The drug analyte detected in this assay, 9-carboxy THC, is a metabolite of delta-9-tetrahydrahydrocannabinol (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 9-carboxy THC metabolite can be detected in urine for several weeks.  Normalization of results to creatinine concentration can help document elimination or suggest recent use, when specimens are collected at least one week apart
INDICATIONS FOR USE: Results are intended to provide the physicians/ clients of Saint Francis Health System with clinical interpretation of the results obtained from the analysis of a urine specimen for the presence and/ or absence of prescribed drugs and their metabolites.  This test is not intended to be used as a pre-employment screening assay or for legal forensic purposes.