Presence of nicotine is indicative of the consumption of tobacco and tobacco products. Cotinine is the name of the substance formed by nicotine on entering the body. The test is a very simple one, commonly used and is readily available. However, it must be noted that nicotine can be found in body not necessarily due to the consumption of tobacco products. Nicotine is also present, though in small quantities, in products like tomatoes, peppers, potatoes and coca leaves.