To create a deep red colour he went on a beetroot diet for a week, and for a striking bright green sample downed litres of Berocca and celery juice for days on end.
"If you can get past the fact that this is urine in a test tube, it is very pretty and aesthetically pleasing," he told the Herald on Sunday. "It is definitely art and has been recognised as such.
"My biggest concern was when I was drinking so much beetroot juice and my pee went a very scary colour of red. I started to get a bit paranoid there was something seriously wrong. There was also an awful lot of test tubes full of the stuff in my flat."
Award judges were Dunedin Public Art Gallery director Cam McCracken, Real Art Roadshow director Fiona Campbell and Wellington art curator and writer Brian Wood, who said Irvine's effort "shone through".
Irvine's winning photograph is available to buy from an exhibition at the Russell Henderson Art Gallery in Alexandra for $450.
"I am hoping an idea for a follow-up masterpiece will come to me the next time I'm in the pub," Irvine added.