超声微波辅助萃取与冷冻预浓缩在挥发性有机物分析中的应用研究

发布时间：2018-07-03 05:58

本文选题：超声微波辅助萃取 + 固相微萃取　；参考：《浙江工业大学》2017年硕士论文

【摘要】：微波辅助萃取(microwave assisted extraction,MAE)作为一种高效的萃取技术,已在天然产物萃取和食品药品分析领域得到了广泛应用。相比静态微波萃取模式,超声微波辅助萃取(ultrasonic/microwave asstited extraction,UMAE)具有更明显的优势,因为超声加快了目标化合物的传质速度,降低了热不稳定化合物因长时间微波照射而引起的降解。在已发表的关于超声微波辅助萃取的研究中,萃取剂一般采用水或者传统的有机溶剂,本文引入低共熔溶剂(deep eutectic solvent,DES)对植物样品进行预处理,使得提取出的挥发性有机物(volatile organic compound,VOC)更为丰富,精油得率更高。环境中VOC主要使用气相色谱质谱联用(gas chromatography-mass spectrometry,GC-MS)法进行检测,VOC直接进入仪器会出现信号响应不高,质谱分辨率差,仪器受样品湿度影响大等问题,通过三级冷阱技术净化和浓缩样品,使得上述问题得到改善。本文具体内容如下:1)建立了一种以DES为基础的微波辅助水蒸汽蒸馏(deep eutectic solvent-microwave assisted steam distillation,DES-MASD)提取八角茴香挥发性精油的方法。对萃取过程中的参数进行了优化。在最优条件下对八角茴香进行挥发性精油的提取,DES-MASD的精油得率为5.3%,MASD的精油得率为3.0%,两者结果有着明显差别。精油组分的分析,DES-MASD能得到较MASD更多的挥发性物质。实验结果表明,DES-MASD是一种新型的高效提取八角茴香挥发性精油的绿色前处理技术。2)建立了一种新型的以DES为基础的超声微波协同-顶空固相微萃取(deep eutectic solvent-ultrasonic/microwave asstited steam distillation-headspace solid phase microextraction,DES-UMASD-SPME)结合GC-MS的方法分析测定八角茴香中的挥发性精油成分。采用单因素实验对影响该方法的因素进行了优化。将最优条件下得到的样品分析结果与DES-MASD进行了比较,DES-UMASD-SPME法使用更少的样品消耗更低的DES体积和更短的萃取时间。结果表明:DES-UMASD-SPME是一种快速、高效的实验方法,可以快速的对八角茴香进行提取和分析挥发性成分,消耗样品量少,没有污染,符合绿色分析化学的需求。3)建立了一种三级冷阱技术参与的环境中VOC的富集与检测的方法。优化了大气预浓缩仪的三级冷阱的捕集温度,对TO15标气进行了一系列测试:绘制了标准曲线(0.5-10 nmol/mol)得到了目标化合物的平均相对响应因子(average relative response factor,ˉˉˉˉˉRRF),它们的相对标准偏差(relative standard deviation,RSD)在4.47-28.12%之间;方法的精密度为2.81-18.68%;方法的检出限(method detection limit,MDL)为0.22-2.17 nmol/mol;通过中低两个水平浓度的加标,得到方法的回收率为72.51-113.67%。对某工厂的环境空气样进行了检测,得到结果有高浓度的N,N-二甲基乙酰胺存在。以上实验结果表明,三级冷阱前处理参与的环境中VOC的富集与检测方法是一种高效可靠的方法,它的检测限低,灵敏度高,不消耗有机试剂没有污染,符合环境中VOC监测的需求,符合绿色分析化学的需求。
[Abstract]:Microwave assisted extraction (MAE), as an efficient extraction technology, has been widely used in the field of natural product extraction and food and drug analysis. Compared with the static microwave extraction model, ultrasonic microwave assisted extraction (ultrasonic/microwave asstited extraction, UMAE) has a more obvious advantage because of ultrasound. The mass transfer speed of the target compound was accelerated and the degradation of thermal unstable compounds caused by the long time microwave irradiation was reduced. In the published study on ultrasonic microwave assisted extraction, the extractants generally used water or traditional organic solvents. This paper introduced the low eutectic solution (deep eutectic solvent, DES) to plant samples. The extraction of volatile organic compounds (volatile organic compound, VOC) is more abundant and the yield of essential oil is higher. In the environment, VOC is mainly detected by gas chromatography-mass spectrometry (gas chromatography-mass spectrometry, GC-MS), and VOC directly enters the instrument with low signal response, poor resolution of mass spectrometry, and instrument sample. The problem is improved by purifying and concentrating samples by three stage cold trap technology. The contents of this paper are as follows: 1) a DES based microwave assisted steam distillation (deep eutectic solvent-microwave assisted steam distillation, DES-MASD) is established to extract the volatile essential oil of the star anise The parameters in the extraction process were optimized. Under the optimal conditions, the extraction of volatile essential oil from the star anise was obtained, the yield of essential oil of DES-MASD was 5.3% and the yield of essential oil of MASD was 3%. The results of the two were distinctly different. The analysis of essential oil components, DES-MASD could get more MASD volatile substances. The experimental results showed that DES-MA SD is a new green pretreatment technology.2 for efficient extraction of the volatile essential oil of anise fennel. A new type of DES based ultrasonic microwave synergetic solid phase microextraction (deep eutectic solvent-ultrasonic/microwave asstited steam distillation-headspace solid phase microextraction) has been established. The GC-MS method was used to determine the volatile essential oil in the star anise. The factors affecting the method were optimized by single factor experiment. The result of the sample analysis obtained under the optimal condition was compared with that of the DES-MASD. The DES-UMASD-SPME method used less samples to consume lower DES volume and shorter extraction time. Ming: DES-UMASD-SPME is a fast and efficient experimental method, which can quickly extract and analyze volatile components of star anise, consume less sample, not pollute, meet the requirement of green analytical chemistry.3). A method of enrichment and detection of VOC in the environment of three stage cold trap is established. The preconcentration of air Preconcentration is optimized. The capture temperature of the three stage cold trap has been tested for a series of TO15 standard gases: the standard curve (0.5-10 nmol/mol) has been drawn to obtain the average relative response factor of the target compounds (average relative response factor, - to - - - - RRF), and their relative standard deviation (relative standard deviation, RSD) is between the methods. The precision of the method is 2.81-18.68%; the detection limit of the method (method detection limit, MDL) is 0.22-2.17 nmol/mol; the recovery rate of the method is 72.51-113.67%. to a factory's ambient air sample through the addition of two level concentrations at the middle and low levels. The results have high concentration N, N- two methyl acetamide. The enrichment and detection method of VOC in the environment of three stage cold well pretreatment is a highly efficient and reliable method. Its detection limit is low, the sensitivity is high, no organic reagent is consumed and no pollution is consumed. It meets the needs of VOC monitoring in the environment and meets the requirements of green analytical chemistry.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O656

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