Advanced Urine Drug Testing

NOAH Clinical Laboratory utilizes the latest technology available to detect a wide array of drugs and metabolites in urine samples. We employ modern LC-MS/MS instrumentation to provide results in the quickest, most accurate fashion possible. Use of confirmatory quantitation methods provide many benefits when compared to point-of-care (POC) testing and screening assays.

Download PDF

Applications of toxicology testing include:

Determining whether patients have recently taken their prescribed medication
Discovering if non-prescribed medications or illicit drugs have been used
Monitoring compliance of medications with a high abuse potential
Prevention of misuse, addiction, or diversion
Testing Menu

Benefits of Quantitative Confirmation Analysis with LC-MS/MS

Drug Screen Limitations

Lack Specificity

Drug classes vs. individual drugs

Opiates vs 6-monoacetylmorphine (heroin metabolite)

Cross Reactivity

High concentrations of other drugs can yield false positives

DRI Methadone EIA false positive with Tapentadol and metabolites

Lack Sensitivity

Cutoffs typically lower

Opiate cutoff = 300 ng/mL vs 50 ng/mL

Not Comprehensive

Covers approx. 20 drug classes and without focus on metabolites

Detection of noroxycodone (oxycodone metabolite) would indicate biological metabolism, not spiking of oxycodone into the sample

Semi-quantitative at best

Interpretation of a Positive Drug Screen

  1. Patient is compliant and took the prescription as directed
  2. Patient added drug to the urine after collection
  3. Patient took one dose prior to collection
  4. Patient took another drug which cross- reacts with the test, i.e. a false-positive

Pseudoephedrine can give a “Positive” result for an amphetamine screening test

Interpretation of a Negative Drug Screen

  1. Patient is not compliant
  2. Patient did not follow dosing regimen
    • Less frequent or lower dose
  3. Drug present but below the cutoff
    • Dilute or adulterated urine
    • False-negative
  4. Test does not react with drug of interest
    • Appropriately targeted test may not be available
  5. Altered pharmacokinetic variables
    • Ultra-fast metabolizer – no parent drug present, only me tabolite
    • Poor drug absorption

Strengths of LC-MS/MS Analysis

High specificity

Can differentiate between individual drugs

No cross reactivity

Utilizes 3 unique analyte properties to ID

Increased sensitivity

– Cutoffs are lower than immunoassay techniques

– Reduced false negatives


– Can detect many individual compounds with respective metabolites

– Current capability is 75 analytes


Use of certified reference materials allow accurate quantitative values