Formaldehyde adsorption by karamatsu (Larix leptolepis) bark

Formaldehyde adsorption and release tests of karamatsu (Larix leptolepis) bark and bark ingredients were performed. Karamatsu bark had good formaldehyde adsorption ability that was better than microcrystalline cellulose. An acetone-soluble fraction from karamatsu bark, which might contain bark tannin, had excellent formaldehyde adsorption ability, and was found to release a trace amount of the adsorbed formaldehyde, suggesting that its formaldehyde adsorption was predominantly due to chemical adsorption. It was confi rmed that the acetone-soluble fraction played an important part in formaldehyde adsorption by karamatsu bark. An acetone-insoluble fraction from karamatsu bark had good formaldehyde adsorption ability as well as the bark, in spite of the residue after the removal of the acetone-soluble fraction.