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采用固相微萃取/气相色谱-质谱联用(SPME/GC-MS)对沉香的成分进行研究,建立以特征成分鉴别沉香真伪的方法。通过SPME富集沉香的气味成分,GC-MS测定其化学组成,确定天然沉香的6种特征成分,并通过面积归一化确定特征成分在气味成分中的相对含量;通过沉香样品中气味成分的种类及其相对含量与天然沉香特征成分对比,判断沉香的真伪。SPME/GC-MS法具有样品用量小、操作简便快速、检测灵敏度高、特征性强、结果准确可靠的特点,适用于沉香气味成分的分析及真伪鉴别,且不破坏沉香收藏品的整体结构,已成功用于沉香药材及其工艺品等的真伪鉴别。 相似文献
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WU Hui-qin HUANG Xiao-lan LIN Xiao-shan CHEN Jiang-han ZHU Zhi-xin HUANG Fang MA Ye-fen LUO Hui-tai DENG Xin 《分析测试学报》2012,31(4)
采用固相微萃取/气相色谱-质谱(SPME/GC- MS)方法测定地沟油中的微量杂质成分,通过对各种纯正植物油中的内源性微量成分与不同地区地沟油中的外源性杂质成分的对比分析,以及对地沟油中杂质成分来源的分析,确定了广州、贵州、深圳、北京等地区地沟油的特征成分,并作为鉴别指示成分.该方法灵敏度高、特征性强,在卫生部组织的地沟油检测盲样考核中,对阳性样品判断的准确率高达95.5%. 相似文献
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乌龙茶系半发酵茶,以香高味醇而著称于世.选取肉桂品种的乌龙茶分析其香气成分和香气前体成分,比较两者之间的差异,并通过XAD-2柱层析将香气前体成分进行分离. 相似文献
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分析野生和栽培羌活药材挥发油含量及其组分的变化,为羌活药材的引种栽培及进一步的开发利用提供了依据。采用水蒸气蒸馏法提取羌活药材中的挥发油,通过GC-MS对挥发油成分进行分析鉴定;利用聚类分析对测定结果进行分类;通过相关分析研究海拔对羌活药材挥发油含量的影响。6份药材样品挥发油含量范围为1.60~7.98 mL/100g,6份羌活药材挥发油成分经GC-MS分析,共鉴定出57个化合物,共有成分12个;基于挥发油成分种类及相对含量的聚类分析显示了羌活药材挥发性成分种类及含量的种间差异;相关分析结果表明,海拔高度与挥发油含量存在显著正相关。野生和栽培羌活药材挥发油含量存在差异,总体上野生羌活药材的挥发油含量高于栽培种;羌活药材挥发油含量随海拔升高而增加。 相似文献
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林桂芝 《理化检验(化学分册)》2022,58(2):216-219
硅酸盐岩石样品的主次量成分分析(业内俗称硅酸盐成分全分析)是地质工作的重要内容。通过监测岩石内部成分含量的变化,可以了解相应元素在地壳内的迁移情况和变化规律、元素的集中和分散情况、岩浆的来源及可能出现的矿物相,可进一步解决矿体岩相分带、阐明岩石成因等问题;并且硅酸盐岩石主次量成分的含量是矿物定名时的重要依据[1]。因此,选择能准确测定硅酸盐主次量成分含量的方法非常重要。 相似文献
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Analysis of time series tries to extract tendencies from measured values dependent on time. For this purpose the cusum technique has proved to be a very sensitive tool for the evaluation of both current and completed time series. Even very weak tendencies can be detected at a high level of noise. Time-series analysis further tries to predict values to come from hitherto performed measurements. As a very flexible model exponential smoothing could be successfully used. Even for processes with a high extent of non-stationarity this model allowed a good prediction owing to the dynamics of the process. Three types of time-series analysis, i.e., evaluation of current measurements, retrospective evaluation and prediction of data (also known as “in vivo”, “post mortem” and “in futurum” time-series analysis) are demonstrated for problems stemming from analytical process control. 相似文献
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Vector potential photoelectron microscopy: hyperspectral image processing and super‐resolution applied to images of a Ca–Al alloy intermetallic phase distribution 下载免费PDF全文
Raymond Browning 《Surface and interface analysis : SIA》2015,47(1):63-76
Vector potential photoelectron microscopy (VPPEM) produces four dimensional hyper‐spectral data, and image processing is an integral part of the experimental technique. VPPEM is a new class of instrument, and this is the first discussion of some of the data reduction techniques that have been found effective. The point spread function of VPPEM is multidimensional with a high‐frequency component. Although this high‐frequency component is a small fraction of the total spatial response, images with good signal‐to‐noise can be spatially deconvolved to give super resolution images. The VPPEM data reduction process is illustrated by the analysis of the multiple intermetallic phases in a Ca–Al alloy. These phases have been imaged with better than 0.5‐μ spatial resolution. Not all the problems with the data reduction process have been satisfactorily dealt with, and lessons from this work will influence the design of future instruments. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Recent developments in solid-phase microextraction 总被引:2,自引:0,他引:2
Risticevic S Niri VH Vuckovic D Pawliszyn J 《Analytical and bioanalytical chemistry》2009,393(3):781-795
The main objective of this review is to describe the recent developments in solid-phase microextraction technology in food,
environmental and bioanalytical chemistry applications. We briefly introduce the historical perspective on the very early
work associated with the development of theoretical principles of SPME, but particular emphasis is placed on the more recent
developments in the area of automation, high-throughput analysis, SPME method optimization approaches and construction of
new SPME devices and their applications. The area of SPME automation for both GC and LC applications is particularly addressed
in this review, as the most recent developments in this field have allowed the use of this technology for high-throughput
applications. The development of new autosamplers with SPME compatibility and new-generation metal fibre assemblies has enhanced
sample throughput for SPME-GC applications, the latter being attributed to the possibility of using the same fibre for several
hundred extraction/injection cycles. For LC applications, high-throughput analysis (>1,000 samples per day) can be achieved
for the first time with a multi-SPME autosampler which uses multi-well plate technology and allows SPME sample preparation
of up to 96 samples in parallel. The development and evolution of new SPME devices such as needle trap, thin-film microextraction
and cold-fibre headspace SPME have offered significant improvements in performance characteristics compared with the conventional
fibre-SPME arrangement.
Figure Photo of a high-throughput multi-fibre SPME PAS autosampler 相似文献
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文章介绍了新材料的重要性及发展方向,分析化学在新材料研制中起着耳目的作用,另一方面新材料也为分析化学的进展提供了课题与条件。微量分析、微区分析、表面分析是此领域中的重点。在未来的发展中,分析化学在材料的发展中的地位不会改变,并期待着分析灵敏度与空间分辩率的进一步提高。 相似文献
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面向新世纪的冶金材料分析 总被引:23,自引:1,他引:22
王海舟 《理化检验(化学分册)》2001,37(1):1-4
21世纪冶金材料分析面临复杂体系中痕量元素分析、冶金材料原位分析以及在线实时分析等三大问题。本文对这三方面的发展趋势进行了评述。 相似文献
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Quality evaluation of moluodan concentrated pill using high‐performance liquid chromatography fingerprinting coupled with chemometrics 下载免费PDF全文
Lingyan Tao Qing Zhang Yongjiang Wu Xuesong Liu 《Journal of separation science》2016,39(24):4673-4680
In this study, a fast and effective high‐performance liquid chromatography method was developed to obtain a fingerprint chromatogram and quantitative analysis simultaneously of four indexes including gallic acid, chlorogenic acid, albiflorin and paeoniflorin of the traditional Chinese medicine Moluodan Concentrated Pill. The method was performed by using a Waters X‐bridge C18 reversed phase column on an Agilent 1200S high‐performance liquid chromatography system coupled with diode array detection. The mobile phase of the high‐performance liquid chromatography method was composed of 20 mmol/L phosphate solution and acetonitrile with a 1 mL/min eluent velocity, under a detection temperature of 30°C and a UV detection wavelength of 254 nm. After the methodology validation, 16 batches of Moluodan Concentrated Pill were analyzed by this high‐performance liquid chromatography method and both qualitative and quantitative evaluation results were achieved by similarity analysis, principal component analysis and hierarchical cluster analysis. The results of these three chemometrics were in good agreement and all indicated that batch 10 and batch 16 showed significant differences with the other 14 batches. This suggested that the developed high‐performance liquid chromatography method could be applied in the quality evaluation of Moluodan Concentrated Pill. 相似文献