Abstract

Objective: We present an ultra-sensitive, minimally-invasive method for quantifying cotinine in dried blood spot (DBS) samples as a biomarker of exposure to tobacco smoke that can be collected using a simple heel or finger prick to obtain blood samples.

Methods: Cotinine levels were measured in matched plasma and reconstituted DBS samples from smokers and nonsmokers to evaluate assay parameters. In addition, we applied this new method to finger-prick DBS samples that were collected from infants, children and young adults ages 1–21 to estimate exposure to tobacco smoke. Partitioning of cotinine across red blood cells and haematocrit effects were investigated.