Which of the following is not an excretory product in human urine? 

Human urine contains excretory products such as urea, uric acid, and phosphates.

In humans, urea is the primary nitrogenous waste product produced as a result of protein metabolism. It is produced in the liver and then transported to the kidneys where it is excreted in the urine.

Uric acid is a nitrogenous waste product produced by humans from the breakdown of purines, which are found in many foods, particularly those high in protein.

By excreting excess phosphates in the urine, the kidneys play an important role in regulating the balance of phosphates in the body.

Ammonia is not a product excreted in human urine. Ammonia is a highly toxic substance that in the liver is rapidly converted to urea and then excreted in the urine.