When did doofenshmirtz first use his shrinkinator?

Dr. Heinz Doofenshmirtz first used his shrinkinator in the "Phineas and Ferb" episode titled "Ferb Latin," which is the 18th episode of the first season. The episode originally aired on September 29, 2007. In this episode, he aims to shrink his nemesis, Perry the Platypus, using the device.