<論文・報告>光応答するコナラ起源VOCの放出特性について

Abstract

わが国の優勢樹種であるコナラから放出されるVOCs(揮発性有機化合物)濃度をPTR-MS(陽子移動反応質量分析計)により測定した. これまでの研究からコナラからのイソプレン放出は既存のモデルには従わないことが示唆されている. より正確なオゾン生成ポテンシャルなど大気質モデルの構築のため, VOC放出挙動についての調査を行った. 温度および光強度を制御してコナラ由来のVOCの中でも主にイソプレンに着目し測定した結果, イソプレンの放出挙動には2種類存在する可能性が示唆され, これらの放出挙動について調査しモデル構築を試みた. モデル構築の結果, 放出挙動については実測と近い挙動が得られたが放出量に関しては今後情報を集める必要があると考えられる.

VOCs (Volatile Organic Compounds) emitted from Quercus serrata, a dominant tree species in Japan, were analyzed using a proton-transfer-mass spectrometry (PTR-MS). Previous studies suggested that isoprene—predominant VOCs released from Quercus serrata—does not follow the current model, and we investigated the VOC release behavior in order to construct an air quality model for the prediction of accurate ozone generation potential. We measured the emission of isoprene, a representative VOC emitted from Quercus serrata, under the control of temperature and light intensity. As a result, there were two kinds of isoprene release mechanisms, and we investigated their processes and we tried to construct a release model. In the models we established, a relative variation of the calculated isoprene emission was similar to that measured, but absolute values of the calculated isoprene emission was not in agreement with those observed. We concluded that it was necessary to obtain more information on isoprene emission from Quercus serrata.