you use a urine test strip or a test kit from EXIT international (more expensive, same shit). If you have powdered N, you can perform a test for purity. there is no need to perform this test on a brand new, unopened and sealed veterinary product. It is from a LEGIT company and they would be in serious breach of laws if they didn't produce what they said they did. a genuine manufacturer who provides to the veterinary companies isn't going to produce poor quality products, absolutely no point whatsoever. and anyone who tells you different is full of BS. you can't buy poor quality N, and if you read it on here its just made up to scare people. I know this as i have some