Two steps in detecting and removing cat urine
Sometimes you suspect that either your cat or an intruding cat has sprayed urine in your home. You can’t be sure but you think it might be there but you can’t see it. You can do two things to find it and get rid of it.
Detecting cat urine
Ultraviolet light, also known as blacklight, causes phosphorus and proteins in a cat’s urine to glow which makes it relatively easy to detect. Even if it’s been cleaned, but not using an enzyme cleaner, it will show up under UV light.
Removing cat urine
NOTE: I am a bit dubious about the science which I have mentioned below but it is tricky to get to the bottom of the chemistry involved.
Cat urine is like human urine. It contains concentrated metabolic waste which is made up of urea, creatine, sodium chloride (salt), uric acid, various detoxify substances and electrolytes. The yellow colour comes from a chemical called urobilinogen. Normal urine contains some urobilinogen. It is a colourless byproduct of bilirubin reduction. Cat urine also contains five different bacteria strains.
When urine decomposes it gives off an ammonia odour. Bacteria decomposes the urea and in a second stage of decomposition the urine emits mercaptans (thiols). These are organosulphur molecules composed of carbon, hydrogen and sulphur which give off a pungent odour similar to cabbage or garlic. It is perhaps this smell which gives feline urine is characteristic odour.
Various theories on how enzyme cleaners clean and kill the smell of feline urine
One website says that enzyme cleaners designed to get rid of feline urine operate on it in an enzymatic reaction: the hydrolysis of urea. The enzymes are proteins which speed up the chemical reaction breaking up the urea into carbon dioxide and ammonia. These gases evaporate very quickly. Hydrolysis is a chemical reaction or process in which a molecule of water is added to a substance.
Another website says that enzyme cleaners work by eating the bacteria in the urine. The enzymes effectively consume the bacteria and this, it seems, stops the bacteria decomposing the urea which causes the creation of thiols causing the strong smell.
Another theory comes from a retailer of a super strength enzyme cleaner. They state on Amazon that “This spray contains natural enzymatic bacteria that are activated on contact with odors and stains, feeding on ammonia crystals and organic matter until they are completely eliminated”.
Your guess is as good as mine. One thing is for sure: it works. I can vouch for it. It is cheap too so I wouldn’t bother making some homemade stuff.