thrival

I've been distilling urine into ammoniated water to extract its salt. To increase the ammonia concentration, when I distill again, should I throw out the first water or the last? In other words does the ammonia gas come over in the beginning of the distillation, at the end, or equally throughout? I've seen the above posting, et al, I just want to keep this simple, not go out for long distillation trains, columns, equipment, etc. Thanks.