Abstract
We developed a sensor element for formaldehyde. The sensor element was made of a porous glass which was impregnated with both ammonium ion and β-diketone. Acetylacetone, 1-phenyl-1,3-butandione and 1,3-diphenyl-1,3-pentandione were investigated as the diketone. The color of sensor elements changed from colorless to yellow after exposure to formaldehyde with the peak wavelengths of 407∼425 nm. There were linear relationships between the absorbance of 407∼425 nm of sensor elements and accumulated concentration of formaldehyde. The value of absorbance change was about 1 for the accumulated exposure of 90∼140ppb×24hour for the acetylacetone or 1-phenyl-1,3-butandione impregnated sensor element.
