>>12276093You could try getting it from urine if you want to really go a DIY route, but that takes a long time and keeping around weeks old urine is probably not tenable.
I've also heard of limited success by burning high protein content organic material like onions beans in a low oxygen atmosphere and bubbling the gases/smoke through water. The nitrogen in the amino acids gets partially oxidized into various NOx forms and dissolves in the water to give you a mix of nitric/nitrous acid. I think adding hydrogen peroxide to this might be enough to bump the NO2- to NO3-, but less confident about that. You'd probably have to distill this afterwards to remove most of the junk that also comes over from burning organics, and I bet you'd still get some hydrocarbons coming over. Not sure how to deal with those, but if you just want low-medium strength nitric acid this would work.
