The oxidation of ethanol to acetaldehyde was previously investigated in a continuous flow bench scale reactor using a zirconium-oxide-supported vanadium catalyst. Products were analyzed by near-infrared spectroscopy, a fast and accurate tool for the determination of water, ethanol, and acetaldehyde content. Water content was calibrated by Karl Fischer titration while gas chromatography was used to calibrate ethanol and acetaldehyde contents. Near-infrared spectroscopy is a fast, cost-effective method for the determination of water, ethanol, and acetaldehyde products from partial ethanol oxidation.