Abstract: Apparatus for measuring liquid aldehydes includes a liquid sample pouring mechanism for dividing a liquid sample which contains aldehydes into a formaldehyde measuring liquid sample and a total aldehyde measuring liquid sample and pouring the liquids separately from each other; a formaldehyde measuring mechanism for measuring the liquid formaldehyde in the formaldehyde measuring liquid sample; a total aldehyde measuring mechanism for measuring the liquid aldehydes in the total aldehyde measuring liquid sample; and a formaldehyde ratio calculating mechanism for calculating the ratio of the formaldehyde to the total aldehyde from the results of the measurements of the respective aldehyde measuring mechanisms.

Abstract: An apparatus for detecting gaseous aldehydes is disclosed which contains a detachable aldehyde capturing system and an aldehyde detection system. The gaseous aldehyde is passed across a semipermeable membrane with a solvent on the other side of this semipermeable membrane to dissolve and absorb the aldehydes from the gas. This system permits the concentration and detection of low concentrations of gaseous aldehyde in the sample for efficient measurement. The aldehyde dehydrogenase to produce NADH in an amount corresponding to the amount of aldehyde in the solvent. The aldehyde detection system measures the amount of NADH produced.