The NH4OH (ammonia) is no big deal, but the H2SO4 (Sulfuric acid) is some highly caustic stuff. It can literally melt flesh off the bone and rubber off the soles of shoes. If that is required to "properly" extract nic from tobacco, then yeah, that is NOT going to be feasible for....really anyone as a DIY process. There has to be a safer method, even if less efficient.
gonna pick on ya for this one..... caustic is for base pH items such as sodium hydroxide ( lye) ... ( pH above 7.0)
( Im gonna blame it on that its been YEARS since you took chemistry