Proton-Transfer Chemical-Ionization Mass Spectrometry Allows Real-Time Analysis of Volatile Organic Compounds Released from Cutting and Drying of Crops
详细信息 查看全文
- 作者：Joost A. de Gouw ; Carleton J. Howard ; Thomas G. Custer ; Bradly M. Baker ; and Ray Fall
- 刊名：Environmental Science & Technology
- 出版年：2000
- 出版时间：June 15, 2000
- 年：2000
- 卷：34
- 期：12
- 页码：2640 - 2648
- 全文大小：208K
- 年卷期：v.34,no.12(June 15, 2000)
- ISSN：1520-5851
文摘
The wounding and drying of plant material during cropharvest could be a significant source of volatile organiccompounds (VOCs) that enter the atmosphere. Here, weshow that these primarily oxygenated VOCs can be measuredusing proton-transfer chemical-ionization mass spectrometry(PT-CIMS), a method that allows online and simultaneousmonitoring of oxygenated VOC levels. For clover, alfalfa, andcorn, leaf wounding and in particular drying were shownto lead to strongly enhanced emissions of a series of C6aldehydes, alcohols, and esters derived from (Z)-3-hexenal. Additionally, for the forage crops clover andalfalfa, enhanced emissions of methanol, acetaldehyde,acetone, and butanone were observed. The identities of themeasured carbonyl compounds were confirmed using high-pressure liquid chromatography. For clover, initial cuttingled to a VOC release of about 175 
g of C (g dry wt)-1, whileduring drying the cut clover released >1000 g of C (gdry wt)-1; qualitatively, similar amounts of VOCs were releasedfrom alfalfa, the major hay crop in the United States.The atmospheric implications of these findings may includeeffects on the local air quality in agricultural areas,contributions to long-range transport of pollutants, andeffects on the formation of HOx (=OH + HO2) radicals inthe upper troposphere.
g of C (g dry wt)-1, whileduring drying the cut clover released >1000 g of C (gdry wt)-1; qualitatively, similar amounts of VOCs were releasedfrom alfalfa, the major hay crop in the United States.The atmospheric implications of these findings may includeeffects on the local air quality in agricultural areas,contributions to long-range transport of pollutants, andeffects on the formation of HOx (=OH + HO2) radicals inthe upper troposphere.