基于“成分-药效”关联分析的六味地黄丸质量控制方法

本文以中药复方制剂六味地黄丸为研究示例,分别进行六味地黄丸药效成分明确化鉴别、典型药理模型的药效实验、成分与药效的关联分析,共鉴别出六味地黄丸中16个成分.通过成分与药效的关联性分析,得出4个与典型药理模型药效相关的成分.建立了指标性成分的含量测定方法学,通过"成分与药效"的关联性分析所得出指标性成分的含量测定方法,可实现对中药复方制剂六味地黄丸的质量控制.     

SPME/GC-MS鉴别沉香真伪方法研究

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。     

五味子优良品种优选的模式识别方法

通过超高效液相色谱法,对不同生长特征的五味子样品中5种主要的木脂素成分:五味子醇甲、五味子醇乙、五味子酯甲、五味子甲素和五味子乙素进行测定,同时考察其抗氧化活性。 对所得到的5种木脂素成分的含量及抗氧化数据进行聚类分析和主成分分析,并且通过逐步判别分析建立判别函数,从而筛选五味子优良品种。 主成分分析和聚类结果基本一致,均将样品分为3大类,逐步判别分析的正确率高达90%。     

A Novel Method for the Identification of Gutter Oils Using SPME/GC - MS ( Ⅱ )

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％.     

SPME/GC-MS鉴别地沟油新方法(Ⅱ)

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%。     

野生与栽培羌活药材挥发油含量及组分的比较分析

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。     

分子轨道成分的计算

量子化学文献中经常涉及到“分子轨道成分”概念, 然而相应的计算方法却没有普遍得到重视, 甚至存在严重误区. 专门对分子轨道中基函数的成分、原子轨道的成分以及原子的成分这些基本概念和计算方法进行了详细讨论, 通过实例分析比较了不同方法间的差异, 同时指出了计算和分析时需要注意的问题, 给出了在方法选择上的建议.     

乌龙茶肉桂香气前体成分分析

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.     

X射线荧光光谱法测定硅酸盐岩石中主次量成分结果异常时的质量控制北大核心CSCD

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。     

基于光热诱导红外和热重-质谱联用的聚合物成分结构剖析

材料的结构和成分是决定材料物理化学性质的关键因素,然而高分子材料成分以碳、氢、氧为主,通过成分分析很难确定材料的结构组成.红外光谱技术与热分析技术是分析高分子材料结构信息的重要表征手段.然而传统红外光谱技术对样品要求较高,很难在不破坏样品的情况下直接进行测试.本文采用一种新型光热诱导红外光谱技术在不破坏样品的前提下直接...     

Time-series analysis in analytical process control

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.     

Vector potential photoelectron microscopy: hyperspectral image processing and super‐resolution applied to images of a Ca–Al alloy intermetallic phase distribution

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.     

Recent developments in solid-phase microextraction

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     

新材料的发展与分析化学

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。     

非终点滴定法与其应用

为了实现滴定分析的快速和自动化,本文借鉴以往研究的经验针对其不足[1~8],提出了一种新的分析方法,滴定中只要加二次标准液,将采集到的数据通过适当的数学计算,即可得到样品液的浓度,本法不需要已知反应常数、电极转换系数等,对中和度没有严格要求[9~11],故具有可操作性和实用性。本法不需要确定终点,不需要全过程滴定,为滴定分析的自动、快速化提供了充分的条件,特别适合冶金、环境、食品、药品的大批量快速分析和在线分析。根据该方法的原理即可开发出一种新的自动分析仪。     

化学分析中的某些现象

叙述了日常化学分析中所遇到的某些特殊现象,提出了一些解释并展开了讨论     

面向新世纪的冶金材料分析

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。     

Quality evaluation of moluodan concentrated pill using high‐performance liquid chromatography fingerprinting coupled with chemometrics

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.