Whiff of Death

Whiff of Death by Isaac Asimov. mass_market edition. ISBN: 9780449236604.

Everyone knew that Ralph Neufeld was a careful young chemist, especially his professor, Lou Brade. Thats why Ralphs accidental demise due to a confusion of chemicals struck Brade, as well as the police, as highly unlikely. Someone on campus had, somehow, switched bottles on poor Neufeld, and the result was as deadly as had been planned. The trouble was all the right suspects were in the wrong places when it happened...all the wrong suspects had the right motives...and the one person most qualified to solve the crime was already being considered the killer!