With James Irvine, Purdie is known for his work on understanding the chemical structure of simple sugars.

[1][2] The building that houses the School of Chemistry (that he helped found) at the University of St Andrews bears his name.

[4] Around 1871, he joined the Royal School of Mines under Frankland in London, then went to Würzburg University in Germany where he received a doctorate (PhD) in Chemistry.

[5] In 2014, during a clear-out at St Andrews an early periodic table wall chart was found, established to have been purchased by Purdie in 1885.

He is buried with his parents in the eastern cemetery extension to St Andrews Cathedral churchyard.