Forensic Urine Chromatography

Urine Toxicology Screening by Gas Chromatography Mass Spectrometry

Urine Toxicology Screen provided by Dynacare incorporates gas chromatography and mass spectrometry (GC-MS) for the qualitative identification of >100 different drugs and drug metabolites.  Analyte identification is based on mass fragment identification within a defined GC-MS spectral library.

We note that the ability to detect any drug or metabolite in urine is dependent on many factors, including:

• the dose ingested
• the analytical method used
• the sensitivity of the method used for the analyte of interest
• the individual’s metabolic variability - genetic factors, age, gender, etc.
• the individual’s physical condition – most notably kidney and liver disease
• the amount of fluid ingested
• the method and frequency of dosing
• the time the drug was ingested relative to the time the urine sample was collected

The GC-MS Urine Toxicology screen provided by Dynacare can detect use of the specific drug and drug metabolites listed in the tables below.

It will not identify every licit and/or illicit drug that might be in a urine sample.

If the drug of interest is not listed in the tables below it will not be detected by this screen, at this time.

If a listed analyte was detected in the urine the specimen that analyte will be reported as POSITIVE. 

Positive result indicates that the analyte is present in the customer’s urine at a minimum concentration above its screening threshold.  A positive result does not indicate the analytes route of administration, ingested dose, concentration in the urine or the customer’s level of intoxication.

A negative result may not necessarily mean that the urine is drug-free. Negative results can obtained when the drug is present in the urine, but at a concentration that is below the sensitivity of the method.  This is especially true for benzodiazepine and barbiturate drugs, as this screening method has relativity poor sensitivity for these drug classes.  Negative results may also be obtained if the specific analyte of interest is not included in the GC-MS Urine Toxicology screen provided by Dynacare.

Table 1: Summary of the different drugs and drug metabolites included within the Dynacare GC-MS Urine Toxicology Screen