Apparatus for measuring aldehye

A continuous aldehyde measuring apparatus comprising:

• a gaseous aldehyde capturing means comprising an aldehyde capturing solvent and a semipermeable membrane for continuously capturing aldehyde in a gaseous sample, whereby the gaseous sample is separated from the aldehyde capturing solvent by the semipermeable membrane;
• a gaseous supply means for delivering a gaseous sample to said gaseous aldehyde capturing means;
• a sample dividing means for continuously dividing the aldehyde capturing solvent into two samples, said two samples comprising a formaldehyde measuring sample and a total aldehyde measuring sample, and said sample dividing means pouring the formaldehyde measuring sample and the total aldehyde measuring sample separately from each other;
• a formaldehyde measuring means for receiving and measuring the formaldehyde in said formaldehyde measuring sample in which liquid formaldehyde is reacted with NAD in the presence of formaldehyde dehydrogenase to produce NADH;
• means for measuring total aldehyde comprising means for receiving and measuring the total aldehyde measuring sample wherein the total aldehyde measuring sample is reacted with NAD in the presence of aldehyde dehydrogenase immobilized in an enzyme reactor to produce NADH;
• connector means between said gaseous aldehyde capturing means and the aldehyde measuring means whereby the gaseous aldehyde capturing means is readily separated from the aldehyde measuring means;
• a gaseous sample discharge means for removing gaseous samples from said gaseous aldehyde capturing means;
• a pressure valve provided at said gaseous sample discharge means to control aldehyde capturing ratio of said gaseous aldehyde capturing means by varying the gas pressure in said gaseous aldehyde capturing means;
• compensating gaseous supply means for delivering gas free of aldehyde to said gaseous aldehyde capturing means;
• a switching cock means in said gaseous supply means for alternatively supplying either gaseous sample or gas free of aldehyde to said gaseous aldehyde capturing means;
• and
• a formaldehyde ratio calculating means for calculating the ratio of said formaldehyde to the total aldehyde in the sample using the results of the measurements of the amount of NADH by the means for measuring total aldehyde and the formaldehyde measuring means.