Which biomarker testing method provides quantitative results?

Gas chromatography/mass spectrometry (GC/MS) is a highly sophisticated analytical method that is particularly effective for quantifying various substances, including drugs and metabolites, in biological samples. In GC/MS, samples are vaporized and then separated in a gas chromatograph, where they are identified based on their mass-to-charge ratio in the mass spectrometer. This process allows for precise quantification due to its high sensitivity and specificity, making it a standard method in toxicology and drug testing.

In contrast, saliva tests, hair analysis, and urinalysis can provide qualitative or semi-quantitative results but may not offer the same level of precision in quantifying specific biomarkers. For example, while urinalysis can detect the presence of substances, it might not always provide precise measurements of concentration without further analytical techniques. Hair analysis mainly provides insights on long-term exposure rather than immediate quantification of drug levels.

Thus, GC/MS stands out as the method that delivers quantitative results, supporting clinical and forensic assessments with a high degree of accuracy.