I've got some 'huile de serpent' if you want some - guaranteed to increase your sex appeal.
Unless you're planning on racing your car, or need temperature/pressure control to within 0.1c/psi then 'pure'
nitrogen inflationwon't offer much. After all the air we breathe is about 78% nitrogen already (Nitrogen: 78.09%, Oxygen: 20.95%, Argon: 0.93%, Carbon dioxide: 0.038%, Neon, Helium, Krypton, Hydrogen, Xenon, etc.).
You'd also have to make sure that you only top up with pure nitrogen to maintain those 'benefits'.
You'd be better off filling them with pure helium to reduce the weight of the car
It won't do any harm though, and it's what Costco put in mine (no charge as they do it as standard) when I put the SuperSports on.