The Nicotine and Cotinine Serum/Plasma Test measures levels of nicotine and its metabolite cotinine in the blood to evaluate tobacco exposure. Cotinine provides a reliable marker due to its longer half-life, distinguishing active smoking from secondhand smoke exposure. This test supports assessment of nicotine dependence, monitoring of cessation efforts, and evaluation of environmental or occupational smoke exposure.

The Nicotine and Expanded Metabolites Test uses LC-MS/MS to detect nicotine, cotinine, and a broad panel of related metabolites in biological samples. This sensitive assay distinguishes recent and past exposure from environmental or active smoking, supports biomarker validation, and clarifies metabolite profiles. It aids clinical and research evaluation of tobacco use, nicotine metabolism variation, and exposure assessment.