thank you for your question. It triggered me to search on the topic and here is a relevant finding:
"The plasma half-life of nicotine after intravenous infusion or cigarette smoking averages about 2 h. However, when half-life is determined using the time course of urinary excretion of nicotine, which is more sensitive in detecting lower levels of nicotine in the body, the terminal half-life averages 11 h (
Jacob et al. 1999). The longer half-life detected at lower concentrations of nicotine is most likely a consequence of slow release of nicotine from body tissues. Based on a half-life of 2 h for nicotine, one would predict accumulation over 6–8 h (3–4 half-lives) of regular smoking and persistence of significant levels for 6–8 h after cessation of smoking. If a smoker smokes until bedtime, significant levels should persist all night. Studies of blood levels in regular cigarette smokers confirm these predictions (
Benowitz et al. 1982b). Peak and trough levels follow each cigarette, but as the day progresses, trough levels rise and the influence of peak levels become less important. Thus, nicotine is not a drug to which smokers are exposed intermittently and which is eliminated rapidly from the body. On the contrary, smoking represents a multiple dosing situation with considerable accumulation while smoking and persistent levels for 24 h of each day."
The half life of a compound been the time it takes for it to decrease by half in the body, by knowing the test sensitivity you can predict how long time before the test you need to stop nicotine for the test to be negative. The terminal half-life is 11h00 here.... Because nicotine accumulate in tissues (I suppose fat tissues), depending on your body weight fat ratio, nicotine cessation, daily exercising, detox diet (raw beets or juiced for example) 1-2 weeks before the test should come up clean. Also, drinking a lot of water before the test, will dilute your urine. Finally, never collect the beginning of the urine flow but just the end of it to be tested. I wonder why nicotine is tested so the challenge seems a bit awkward to me. Good luck anyway!