Confirmatory testing

True confirmatory testing uses a testing protocol that identifies a drug to the exclusion of all others. At STL, confirmatory testing is performed using liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). In any urine drug testing program, identifying a drug with this methodology establishes absolutely that the donor of the specimen used the drug identified to the exclusion of all others.

This testing is quantitative. The resultant value is then used to address any quantitative drug issues, i.e. active use verses passive exposure, new verses residual use (see explanations for each of these here [another hyperlink]).