小花蔓澤蘭慢速熱解及其醋液應用於小黑蚊防治之初探

Abstract

為開發入侵植物小花蔓澤蘭(Mikania micrantha Kurth)之用途，本研究以慢速熱解法將小花蔓澤蘭以機械窯在升溫速率100℃/hr，每階段均持溫1 hr下，於150-200℃、200-250℃、250-300℃、300-350℃、350-400℃、400-450℃、450-500℃、500-550℃及550-600℃等溫度範圍分段收集，及在150-350℃和150-600℃等兩種方式一段收集，共得11種小花蔓澤蘭粗醋液，探討其不同最終溫度和不同收集溫度範圍之小花蔓澤蘭粗醋液原液及經76 mmHg及50℃減壓蒸餾後蒸餾醋液之基本性質。此外，並分析由150-350℃收集之小花蔓澤蘭粗醋液稀釋5倍濃度後，對於防治小黑蚊之可行性。試驗結果得知，小花蔓澤蘭之化學組成分中，全纖維素、α-纖維素、木質素、乙醇-甲苯抽出物及灰分含量分別為54.57、35.32、25.22、7.44及9.36%。小花蔓澤蘭粗醋液之基本性質中，以150-600℃分段收集後之總收率達42.63%，且於150-300℃收集者約佔總收率的70%以上，而一段收集者150-350℃之收率為30.31%，150-600℃則為37.09%；又收集溫度高於400℃時，粗醋液pH值均高於8，且顏色會呈現深褐色；有機酸含量以250-300℃者為最高達5.93%；隨著收集溫度的提高，粗醋液之含水率會逐漸減少，而比重和溶解焦油含量則會逐漸增加，並均以550-600℃收集者為最高；將小花蔓澤蘭粗醋液經減壓蒸餾後，所得之蒸餾醋液的比重、有機酸含量和溶解焦油含量均明顯低於粗醋液者，且顏色會呈現澄清透明。小花蔓澤蘭粗醋液之有機成分可鑑定出47種，可分為酸性物質(acidic components)、酚性物質(phenolic components)、含氮物質(nitrogenous components)和中性物質(neutral components)等4大類，在150-350℃和150-600℃ㄧ段收集者，分別以醋酸、酚、吡啶和2-糠醇含量為最多；收集溫度在400-600℃時，其酸性物質的含量會降低，而含氮物質如吡啶和乙腈等衍生物含量則會增加；蒸餾醋液中之150-350℃和150-600℃ㄧ段收集者有機成分仍以醋酸含量為最多，但較大分子量之化合物如2,6-二甲氧基酚(2,6-dimethoxy-phenol)和2-羥基-3-甲基-2-環戊-1-酮(2-hydroxy-3-methyl-2- cyclopenten-1-one)和部份含氮物質則會被去除。以不同濃度之150-350℃收集小花蔓澤蘭粗醋液抑制青苔生長之試驗結果顯示，以小花蔓澤蘭粗醋液原液和稀釋5倍者，均可有效抑制青苔的生長，藉此阻絕小黑蚊幼蟲之食物來源和繁殖，又以稀釋5倍之小花蔓澤蘭粗醋液進行小黑蚊防治之田間試驗，在每週噴灑一次之連續5週內，小黑蚊密度明顯下降，由平均21.3隻減少至5隻以內，防治率和累進防治率分別可達最高之79.33%和90.61%，當停止噴灑醋液後，小黑蚊之數量雖有緩慢回升現象，但仍低於對照組者，綜合以上初步試驗結果，顯示小花蔓澤蘭粗醋液可用於小黑蚊之防治。

For developing the utilization of M. micrantha, the crude vinegars were made from one step and multi-step collecting methods by slow pyrolysis of M. micrantha using a steel kiln at increasing temperature of 100℃/hr and holding for 1 hr in each collecting step. The eleven kinds of M. micrantha crude vinegars were collected under various temperature ranges of 150-200℃, 200-250℃, 250-300℃, 300-350℃, 350-400℃, 400-450℃, 450-500℃, 500-550℃ and 550-600℃ for multi-step collecting and 150-300℃ and 150-600℃ for one step collecting, respectively. The fundamental properties of M. micrantha crude vinegars and distilled vinegars which prepared under the reduced pressure of 76 mmHg at 50℃ as well as the feasibility of controlling the biting midge using a 5 times dilution of M. micrantha crude vinegar which collected from 150-350℃ were examined. The results indicated that the chemical compositions of the M. micrantha were holocellulose of 54.57%, α-cellulose of 35.32%, Klason lignin of 25.22%, alcohol-toluene extractives of 7.44% and ash of 9.36%. The yield of crude vinegar from 150-600℃ multi-step collecting had the highest one of 42.63% and more than above 70% of total yield was collected at the temperature range from 150-300℃. The yields of crude vinegar collected from one step of 150-350℃ and 150-600℃ were 30.31% and 37.09%, respectively. Among the experimented the crude vinegar collected from 250-300℃ had the highest organic acid content of 5.93%, and from 550-600℃ had the lowest water content, the highest specific gravity and soluble tar content. Furthermore, the crude vinegars collected over than above 400℃ had pH value of above 8 and appeared dark-brown color. In addition, the 47 kinds organic components of M. micrantha crude vinegar were identified by GC-MS analysis, and they could be classified into acidic, phenolic, nitrogenous and neutral compounds. Among them, the acetic acid, phenol, pyridine and 2-furanmethanol were the main compounds in the M. micratha crude vinegar from one step collecting of both 150-350℃ and 150-600℃. The acid compounds of M. micratha crude vinegar collected from 400-600℃ decreased, while the nitrogenous compounds, such as pyridine and acetonitrile increased. After distillation under the reduced pressure, the specific gravity, organic acid content and soluble tar content of M. micratha distilled vinegar were lower than those of crude vinegars. The color of M. micratha distilled vinegars were clear and transparent. Moreover, acetic acid was still the main compound in one step collecting under 150-350℃ and 150-600℃. The higher molecular weight compounds, such as 2,6-dimethoxy-phenol, 2-hydroxy-3-methyl-2-cyclopenten-1-one and parts of nitrogenous compounds were removed after distillation. In addition, using different dilutions of M. micratha crude vinegars collecting from 150-350℃ were applied to inhibit the growth of moss, and the results indicated the original and 5 times dilution of M. micratha crude vinegars could effectively inhibit the growth of moss, i.e. inhibit the food sources and breeding of larva of biting midge. Furthermore, a filed experiment for controlling the biting midge with a 5 times dilution of M. micratha crude vinegar collecting from 150-350℃ was also performed. The results indicated that the density of biting midge decreased significantly from number of 21.3 to below 5 within 5 weeks of continuous spraying vinegar once a week. The controlling rate and progressive controlling rate of biting midge was 79.33% and 90.61%, respectively. After 5 weeks and stop spraying vinegar, the number of biting midge increased slowly, but it was still less than that of the control group. From a preliminary test results, the M. micratha crude vinegar could be used as evading agent for controlling the biting midge.