Yes it can and very quickly.
Can Urine Spoil?
The urine can spoil and the composition will change.
Can urine go bad if in a sealed container
I have always used someone elses pee it never failed me old or I would puy it in my pants every day and freeze it everynight warm it up shake it up its good. Never failed me
If you are trying to save it for a UA, it needs to be refrigerated and used within 24 to 36 hours, the fat may separate and look like lumps floating in it, but you should be able to get it up to body temperature and shake it up....it can be frozen for longer periods of time if needed, I know of people who defrosted it at least 3 months after the fact and it worked fine...hope this was the answer you were looking for!