After Calloway’s initial laboratory screen, it is retested using the most advanced confirmation tests available: Gas Chromatography/Mass Spectrometry (GC/MS) and Liquid Chromatography/ Tandem Mass Spectrometry (LC/MS-MS).

In-house Gas Chromatography/Mass Spectrometry (GC/MS) confirmation testing is available for positive immunoassay screens. Although many confirmation methods are used throughout the industry, GC/MS is considered the “Gold Standard” for quantification.