Emissions of volatile organic compounds from cut grass and clover are enhanced during the drying process

The release of volatile organic compounds (VOCs) by drying grass and clover leaves and stems was studied in the laboratory using proton-transfer chemi cal-ionization mass spectrometry, which enables the simultaneous, on-line m onitoring of VOC concentrations. A burst of VOC emissions due to cutting th e leaves and stems was followed by a second, more intense emission lasting for several hours when the vegetation was starting to dry out. In addition to (2)-3-hexenal, (Z)-3-hexenol, and hexenyl acetate, that were emitted by the plans tissue in response to the wounding, enhanced emissions of methano l, acetaldehyde, acetone, butanone, and possibly formaldehyde were observed . These findings may have important implications for regional air quality i n agricultural and urban areas.