Cortana may refer to: 1  Cortana (software), Microsoft personal assistant software. 2  Cortana (Halo), a fictional artificial intelligence character. 3  Cortana (gastropod), a gastropod genus.  Cortana, or Curtana, a ceremonial sword used in the coronation of British 1  monarchs. Cortana Mall, Baton Rouge, Louisiana,  USA.
The length of time that nicotine stays in the body and cotinine can be a reliable indicator of nicotine use depends on the amount of tobacco smoked, the number of years smoking tobacco, and the type of nicotine test performed. It can be as short as 2 days, or as long as 3 months.
Sorry to split hairs on this, but given that the typical half-life of nicotine is 2 hours, and that most assays have a limit of detection of 0.1 to 0.5 ng/ml, following the logic I described above, all the nicotine has gone from the blood stream within 24 hours. i.e. when you take a blood sample from a smoker 24 hours after their last smoke, they will most likely have a blood nicotine level <0.5 ng/ml. (i.e.>95% gone by 24 hrs).