應用SPME-GC/MS與薄膜送樣質譜法探討實木板材之生物源揮發成分

Abstract

揮發性有機化合物（Volatile organic compounds, VOC）通常係指人為排放的VOC，近年來由於全球對於環保議題的關注，環境中的VOC逐漸受到重視。生物源揮發性有機化合物（Biogenic volatile organic compound, BVOC）則係指生物代謝所排放的VOC，屬於植物的二次代謝物，而木材屬於一種生物性材料，具有揮散出此類代謝物之能力，不同於一般建材釋出的VOC，這些芳香氣息係儲存於木材內部，因成分的低沸點、高揮發性的性質而由材面自然揮散，因此隨著木材加工程度的不同，在室內使用的木質地板、壁板、家具及木器等木質材料之加工產品都將具有類似之揮發性。本研究利用便攜式質譜儀（Portable Mass Spectrometer）Kore MS200以及SPME-GC/MS方法，對於紅檜（Chamaecyparis formosensis Matsum.）、台灣杉（Taiwania cryptomerioides Hayata.）、杉木（Cunninghamia lanceolata（Lamb.）Hook.）、柳杉（Cryptomeria japonica D.Don）、台灣櫸（Zelkova serrata Makino.）以及相思樹（Acacia confuse Merr.）等材種的實木板材揮發成分之組成進行鑑別，並探討不同溫度、相對濕度及裝修負荷率等條件對於其揮發性之影響。 各實木板材揮發成分之鑑定，在25 ℃、50 % RH、裝修負荷率13.08 m2/m3的條件下密閉一小時，測得柳杉板材的揮發成分以δ-cadinene（25.85 %）、α-muurolene（18.52 %）、α-cubebene（7.33 %）及β-caryophyllene（4.67 %）為主；杉木板材的揮發成分以cedrene（34.75 %）、β-caryophyllene（12.6 %）、δ-cadinene（10.57 %）及cedrol（6.08 %）為主；台灣杉板材的揮發成分以δ-cadinene（25.43 %）、γ-cadinene（16.97 %）及α-muurolene（11.16 %）為主；紅檜板材的釋出成分以δ-cadinene（30.87 %）、γ-cadinene（12.24 %）及myrtenal（9.36 %）為主；在闊葉樹材的部分僅測得微量的烷烴類、倍半萜類以及SPME熱裂解之化學產物，且整體的訊號量遠低於四種針葉樹板材之數值，可推論台灣櫸與相思樹兩種闊葉板材無顯著的揮發性。 在溫度、濕度以及木材裝修負荷率條件對於揮發性的影響方面，針對柳杉板材β-caryophyllene的揮發量進行探討，得知在柳杉板材在3.34、6.49、9.84、13.08、17.14及20.69 m2/m3的裝修負荷率條件下，隨著裝修負荷率的上升β-caryophyllene的濃度也會隨之提高，濃度在224±115 ppb至1517±215 ppb之間；在50 % RH、柳杉四面壁裝（13.08 m2/m3）條件下，設定15、20、25及30℃等條件進行試驗，β-Caryophyllene的揮發濃度分別為242±65、359±106、1148±230及1764±675 ppb，可得知溫度的高低將顯著影響柳杉板材之揮發性；而相對濕度的變動則對柳杉板材揮發性之影響則較小。

The emission issue of volatile organic compounds (VOC) has been taken attention by the public in recent years, because it may change the indoor air quality and affect human health. Biogenic VOC (BVOC) is one kind of VOC mostly emitted from plant synthesis, which is classified as secondary metabolites. It is called phytoncide when human engage activities in forest. Wood is a biological materials, and has the propensity to emit the volatile content. BVOC is different from the VOC which emit from solvent or coating. Usage of wooden ware, flooring, siding, furniture and decorations indoor have the ability to emit the fragrant smell, to sublimate as BVOC. In this study, the composition of volatile components emitted from different kinds of solid wood panels including Chamaecyparis formosensis Matsum., Taiwania cryptomerioides Hayata., Cunninghamia lanceolata (Lamb.) Hook., Cryptomeria japonica D.Don, Zelkova serrata Makino. and Acacia confuse Merr. was identified by portable mass spectrometer (Kore MS200) and SPME-GC/MS methods, and would be discussed the effect on volatility of temperature, humidity and loading factor of the panels. Under the condition of 25 ℃, 50 % RH insealed container withloading factor 13.08 m2/m3 for 1 hr, the volatile components of C. japonica mainly composed of δ-Cadinene (25.85 %), α-Muurolene (18.52 %), α-Cubebene (7.33 %) and β-Caryophyllene (4.67 %); volatile components of C. lanceolata mainly composed of Cedrene (34.75 %), β-Caryophyllene (12.6 %), δ-Cadinene (10.57 %) and Cedrol (6.08 %); volatile components of T. cryptomerioides mainly composed of δ-Cadinene (25.43 %), γ-Cadinene (16.97 %) and α-Muurolene (11.16 %); and the volatile components of C. formosensis mainly composed of δ-Cadinene (30.87 %), γ-Cadinene(12.24 %) and Myrtenal (9.36 %). Only small amount of alkanes, sesquiterpenoids and the thermal cracking products of SPME were detected from Z. serrata and A. confusa solid wood panels, with measured singal much lower than the results of the four softwood panels. The temperature, humidity and loading factor as variable factors, the volatiles of β-caryophyllene emitted from C. japonica were discussed. It is found that concentration of β-Caryophyllene increases with loading factor. When the loading factor were 3.34, 6.49, 9.84, 13.08, 17.14 and 20.69 m2/m3, concentration of β-Caryophyllene increase from 224 ppb to 1517 ppb. When loading factor 13.08 m2/m3, 50 % RH and temperature were 15, 20, 25 and 30℃, concentration of β-Caryophyllene were 242±65、359±106、1148±230 and 1764±675 ppb respectively, indicating that temperature also significantly affected the volatiles of wood panels. However, the effect of humidity on the volatility was not significant.