Vitamin C, also known as ascorbic acid and L-ascorbic acid, is a water soluble vitamin found in various foods including peppers, kiwifruit, oranges and kale. It is regarded as an essential nutrient to prevent scurvy, involved in the repair of tissue and also thought to lower cancer risk. It is required for the functioning of several enzymes and is important for immune system function. Since it’s isolation in 1928 it was the first vitamin to be commercially produced. Today it is widely available as a dietary supplement. This application brief describes use of a Quasar biphenyl column in the analysis of vitamin C.