發(fā)布時(shí)間：2018-02-05 03:35

  本文關(guān)鍵詞： 高寒草甸 脂肪酸 脂類生物標(biāo)記物 退化 GC-MS　出處：《青海大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：利用脂類生物標(biāo)記物分析環(huán)境變化或溯源有機(jī)物是一種新的研究手段,在高寒草甸退化研究方面還沒有相關(guān)的報(bào)道。本研究針對高寒草甸退化與否存在不同觀點(diǎn)的事實(shí),通過提取和分析植物和土壤脂類物質(zhì),試圖找出反映植被變化的生物標(biāo)記物,為研究高寒草甸退化、合理保護(hù)和可持續(xù)利用提供科學(xué)依據(jù)。通過對植物和土壤脂肪酸提取方法的篩選、反應(yīng)條件的優(yōu)化,確定了最佳的脂肪酸提取方法。對提取的植物和土壤脂肪酸總的分布特征、退化以及未退化高寒草甸植物脂肪酸分布、人工草地植物脂肪酸分布、土壤總的脂肪酸分布、不同深度土壤脂肪酸的變化、退化以及未退化高寒草甸土壤脂肪酸變化以及植物與土壤脂肪酸比較研究等方面進(jìn)行了比較,主要結(jié)果和結(jié)論如下:1.采用HCl-甲醇甲酯化、BF3-甲醇甲酯化以及硅烷化三種預(yù)處理提取植物中的脂肪酸,并使用GC-MS方法進(jìn)行分離和鑒定,結(jié)果表明硅烷化方法效果最差,且會引起色譜柱流失,HCl-甲醇甲酯化、BF3-甲醇甲酯化方法效果較優(yōu),綜合比較可鑒定脂肪酸種類、操作以及安全、回收率后確定較優(yōu)提取方法為HCl-甲醇甲酯化方法。2.對HCl-甲醇甲酯化方法反應(yīng)條件進(jìn)行優(yōu)化,確定植物較優(yōu)反應(yīng)條件為KOH-甲醇溶液加入量為3m L,皂化溫度75℃,皂化時(shí)間5min,HCl-甲醇溶液加入量7m L,甲酯化溫度65℃,甲酯化時(shí)間10min;土壤為KOH-甲醇溶液加入量為1m L,皂化溫度75℃,皂化時(shí)間20min,HCl-甲醇溶液加入量7m L,甲酯化溫度65℃,甲酯化時(shí)間10min。3.對植物脂肪酸進(jìn)行分析,最終確定52種植物共68種脂肪酸,并根據(jù)脂肪酸分布分為微、低、中以及高頻次分布4種類型脂肪酸;對高寒草甸退化以及未退化進(jìn)行了比較,種類上退化高寒草甸高于未退化高寒草甸,含量上未退化高寒草甸要高于退化高寒草甸,進(jìn)一步確定得出退化高寒草甸7種獨(dú)有的脂肪酸,15-二十四烯酸(C24H46O2)、8,8-二甲氧基辛酸(C10H18O4)、壬酸(C9H18O2)、7,10,13-十六碳三烯酸(C16H26O2)、12-甲基十三酸(C14H28O2)、2-羥基十二烷酸(C12H24O3)、3-苯丙酸(C9H10O2)對高寒草甸退化演替具有較強(qiáng)的指示判別功能;對不同草地類型植物花生酸(C20H40O2)含量進(jìn)行了測定,得出退化、未退化高寒草甸以及人工草地之間差異均顯著(P0.05),含量依次為0.4930、0.9470、0.1585mg/g,也可作為高寒草甸退化的重要依據(jù)之一。4.對土壤脂肪酸進(jìn)行了鑒定,共發(fā)現(xiàn)41種,碳數(shù)分布為C3-C28,飽和脂肪酸33種,單不飽和脂肪酸5種,多不飽和脂肪酸3種。土壤脂肪酸種類遵循0-10cm≥10-20cm≥20-30cm規(guī)律;0-10cm土層土壤山崳酸含量(C22H44O2),退化與未退化草甸差異顯著(P0.05),含量依次為4.7、9.6mg/kg。5.植物與土壤脂肪酸比較得出,輕度退化以及未退化高寒草甸脂肪酸種類變化呈現(xiàn)植物≥0-10cm土層≥10-20cm土層≥20-30cm土層;輕度退化草甸中植物與土壤脂肪酸在含量與種類上比較后發(fā)現(xiàn)輕度退化不能得到良好的反應(yīng)。
[Abstract]:The use of lipid biomarkers for the analysis of environmental changes or traceability of organic matter is a new method, which has not been reported in the study of alpine meadow degradation. By extracting and analyzing plant and soil lipids, we try to find out the biomarkers that reflect the change of vegetation in order to study the degradation of alpine meadow. Reasonable protection and sustainable utilization provide scientific basis. The optimum fatty acid extraction method is determined by screening the extraction methods of plant and soil fatty acids and optimizing the reaction conditions. The distribution of plant fatty acids in degraded and undegraded alpine meadow, the distribution of plant fatty acids in artificial grassland, the distribution of total fatty acids in soil, the changes of fatty acids in different depths, The changes of fatty acids in degraded and undegraded alpine meadow soils and the comparison of plant and soil fatty acids were compared. The main results and conclusions are as follows: 1. The fatty acids in plants were extracted by HCl- methanol-methyl methanolation and silanization, and separated and identified by GC-MS method. The results showed that the silanization method had the worst effect. The method of HCl- methanol methyl esterification is more effective and can be used to identify fatty acid species, operation and safety. After recovery, the optimum extraction method was determined as HCl- methanol methyl esterification method. 2. The reaction conditions of HCl- methanol methyl ester reaction method were optimized. The optimum reaction conditions were determined as follows: the amount of KOH- methanol solution was 3m L, the saponification temperature was 75 鈩，

本文編號：1492005