Nothing appears to have happened to your flask of alchemist’s fire.
Wedgerocket’s Alchemial Accident
Level: Sor/Wiz 2
Components: V, S, M
Casting Time: 1 standard action
Target: One unopened flask of alchemist’s fire
Duration: Instantaneous (see text)
Saving Throw: Reflex negates
Spell Resistance: Yes
Wedgerocket, the gnome wizard, is known throughout his homeland of Lantan for his infamous alchemy lab accident. While he was not seriously injured, the explosion did manage to destroy several hundred gold pieces worth of equipment. One bored weekend, he decided to duplicate this effect in a dangerous spell - and as far as anyone knows, it has only ever been used once.
One round after casting the spell on a flask of alchemists’ fire (or if directly strikes a target before this) it explodes violently, dealing 1d6 slashing damage and 2d6 fire damage to any person directly struck (or holding the flask), and 1d6 fire damage to anyone within five feet. The flask explodes at the end of the round after the spell has been cast on it, whether or not the caster is still holding the flask - hence, they would be advised to throw the flask at an enemy soon as possible.
Additionally, anyone suffering fire damage from a direct hit must succeed at a DC15 reflex save or be set alight. Failure means that they take another 1d6 fire damage and remain alight, success means that the flames are extinguished. Each round that the character remains on fire, they must make another DC15 reflex save or take another 1d6 fire damage. (See DMG page 303 for the rules on catching on fire.)
Material component: A vial of alchemist’s fire.