Nicotine is a major constituent of cigarette and tobacco smoke. Many pre-employment drug screening tests check for smoking history of potential employees by detecting the presence of nicotine or its metabolites. In case of nicotine, a metabolite called cotinine is released in the blood stream. The unbound cotinine residues are released into the urine for around 5-6 days. This particular metabolite can be traced easily in the habitual users of tobacco, as it is the principle metabolite of nicotine. Various nicotine tests are based on detection of cotinine in urine samples. These tests often employ immuno-screening techniques coupled with HPLC, RIA, Gas chromatography and Mass spectrometric analysis. A positive detection of cotinine in human urine requires at least 200ng/ml cut-off levels. The major disadvantage of urinalysis is that the urine samples can be easily adulterated or substituted and thus great care should be taken during sample collection and processing.
DNA & Genetics
DNA & Paternity
