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1.
采用傅里叶变换红外光谱直接测定法测定了延胡索及其伪品齿瓣元胡、东北延胡索、土元胡、新疆延胡索及夏天无的傅里叶变换红外光谱,采用主成分析法比较了正伪品之间的差异程度.结果表明基于傅里叶变换红外光谱的主成分分析在反映同属不同种植物化学组成差异程度上具有应用价值.  相似文献   

2.
基于高效液相色谱(HPLC)指纹图谱比较鱼腥草不同部位(茎、叶)化学成分的差异性,并综合评价鱼腥草不同部位的质量。建立鱼腥草不同部位的HPLC指纹图谱,通过相似度评价、化学模式识别及熵权TOPSIS法对其化学成分进行差异性研究,并对其质量标志物(槲皮苷)进行含量测定。建立的HPLC指纹图谱中鱼腥草药材及其茎叶均确定了8个共有峰,指认了其中6个成分;聚类分析(CA)和主成分分析(PCA)结果表明鱼腥草叶和茎的质量差异大,叶和药材的质量较接近;偏最小二乘法-判别分析(OPLS-DA)发现4种成分是造成不同批次样品差异性的主要标志物;熵权TOPSIS法分析显示同批次鱼腥草药材与其茎叶既有相关性也有差异性,且四川产地的鱼腥草药材质量较佳;含量测定结果显示,同批次鱼腥草中的槲皮苷含量由高到低均依次为叶、药材、茎。鱼腥草不同部位HPLC指纹图谱存在显著差异。该方法可反映鱼腥草不同部位质量差异性,为鱼腥草药材的质量控制及资源开发利用提供参考。  相似文献   

3.
采用水平衰减全反射傅里叶变换红外光谱法(HATR-FTIR)测定了同属种子植物中药材菟丝子及金灯藤的FTIR,运用基于连续小波多分辨率分析法对吸收较为相似的菟丝子及金灯藤的FTIR进行特征提取。选择第7、10、13分解层数的特征向量,进行人工神经网络(ANN)训练,再用训练出来的网络对不同产地的植物种子菟丝子和金灯藤所得FTIR小波提取的特征向量进行分类。通过对32个不同样本的验证,说明能够采用基于FTIR-连续小波特征提取及人工神经网络分类法对同科属中药材菟丝子与金灯藤进行识别。  相似文献   

4.
采用静态顶空/气相色谱-离子迁移谱(SHS/GC-IMS)对不同品种雪茄烟叶的挥发性风味化合物构成特点进行了解析,结合阈值和气味属性初步明确了不同品种雪茄烟叶的风格特征,并基于多元统计分析方法筛选不同品种雪茄烟叶的差异风味标志物。共鉴定出82种挥发性风味组分,包括含氮化合物(胺类、吡啶、吡嗪、腈类)、含氧杂环化合物、含硫化合物、脂肪醇、脂肪醛、脂肪酮、脂肪酸、脂肪酯、内酯、单萜烯和芳香族化合物共11类。其中,三甲胺在全部雪茄烟叶中均具有绝对浓度优势和最高的气味贡献度,是雪茄烟刺激性氨味和鱼鲜腥味的主要物质来源。层次聚类分析(HCA)显示,在挥发性组分构成上,楚雪80和楚雪81与多米尼加雪茄烟叶较为相似,其香韵构成丰富,以奶香为主,辅以可可香和辛香;印尼雪茄烟叶独具一格,果甜香特征最突出。基于气味贡献度(OAV)的偏最小二乘判别分析(PLS-DA)显示,三甲胺(氨味、鱼鲜腥味)、3-甲基丁酸乙酯(苹果、柑橘、甜香味)、2,3-丁二酮(黄油、奶油味)、异丁酸乙酯(苹果、热带水果味)、二甲基二硫醚(卷心菜、泥土、硫化物风味)、1-戊烯-3-醇(青草味)、2-甲基丙醛(黑巧克力味)、己醛(青草...  相似文献   

5.
大黄的傅里叶变换红外光谱法快速鉴别   总被引:8,自引:0,他引:8  
利用傅里叶变换红外(FTIR)光谱法对不同的大黄药材进行了分析?结果表明:大黄样品在4000~1800cm^-1区域有相似的红外光谱特征,而在1800~400cm^-1区域不同组系、不同品种的样品又存在很大差异。因此红外光谱法可以快速、简便、直观地对中药材进行质量鉴别。  相似文献   

6.
采用傅里叶变换红外光谱法结合聚类分析对大叶藓及其易混种类(平肋提灯藓、树形疣灯藓、皱叶匐灯藓、尖叶匐灯藓)进行了鉴别。以红外光谱图4 000~500cm-1范围内的吸收峰吸光度为指标,应用组间连接法对5种藓类植物进行聚类分析,结果表明:大叶藓与提灯藓科易混类群距离较远。  相似文献   

7.
建立了适用于元胡止痛口服液原料药材、中间体及制剂中若干生物碱类成分的定量指纹图谱方法。采用DIKMA Diamonsil Plus C18-A色谱柱(4.6 mm×250 mm,5μm),以0.04%乙酸铵溶液(冰醋酸调至pH4.0,A)-乙腈(B)为流动相进行梯度洗脱,在280 nm下进行检测。指纹图谱中含共有峰7个,其精密度、重复性、稳定性的相对标准偏差(RSD)均小于5.0%。对延胡索乙素、去氢延胡索甲素进行定量分析,其分别在6.15~123μg/mL和10.15~203μg/mL范围内线性关系良好,相关系数(r^(2))> 0.999,进样精密度、方法重复性的RSD均小于5.0%,供试品溶液在24 h内稳定。延胡索乙素、去氢延胡索甲素在低、中、高3个加标水平下的平均回收率为89.6%~107%,RSD小于3.0%。所建立的分析方法稳定、准确、可靠,能够对药材、中间体及制剂中的中等极性成分进行检测,可用于考察工业生产中元胡成分的量值传递情况,从而为改进元胡止痛口服液制药过程控制水平提供技术支持。  相似文献   

8.
以不同地理居群的大蒜为研究对象,采用傅里叶变换红外光谱法获取各样品的红外谱图及不同波数下各样品的透过率数据,运用主成分分析及聚类分析等统计学方法对谱图数据进行了比较分析。结果发现,不同地理居群大蒜的红外指纹图谱存在差异,统计学分析结果显示25个品种大致可分为4大类(其中2个样品,4号及25号与这4类间有较大差异),此现象一定程度上反映了大蒜种植地居群环境对大蒜理化性质的影响。  相似文献   

9.
测量不同分辨率下、不同浓度氯仿气体的傅里叶变换红外光谱(FTIR).利用美国环境保护局(EPA)数据库中的数据,通过最小二乘拟合得到不同分辨率下的氯仿浓度,以及线性拟合度和相对误差.分辨率的大小对其计算精确度有一定的影响.选择合适的分辨率对于提高化合物的精确度至关重要.  相似文献   

10.
张滨  张亚兵 《应用化学》1998,15(1):56-58
水稻品种鉴别目前常采用种子形态分析、蛋白和同工酶的聚丙烯酸胺凝胶电泳分析等方法,其缺点是试剂有毒,分析时间长,且很难区别亲缘关系接近的同母异父杂交水稻种子.毛细管电泳是一种高效分离技术【‘’‘〕,具有快速、微量、自动化等优点.本文采用毛细管区带电泳(CZE)对国产13种水稻种子胚乳贮藏蛋白进行初步研究,探讨了作为品种鉴别模式的实际可操作性,以期能为品种鉴别提供新的有效手段.仪器:BiofocusTM3000型(Bio-RadUSA)毛细管电泳仪,配紫外可见检测器和恒温装置.13种水稻种子中包括两组同母异父杂交种子(每组…  相似文献   

11.
A new protoberberine alkaloid,named 5,6-dihydro-10-hydroxy-2,3,9-trimethoxy-13-methyldibenzo[a,g]quinolizinium(1) was isolated from the 60%ethanol extract of the tubers of Corydalis yanhusuo W.T.Wang,together with a new natural product,13- methylpalmatrubine(2).Their structures were established by spectroscopic methods.  相似文献   

12.
Ou J  Kong L  Pan C  Su X  Lei X  Zou H 《Journal of chromatography. A》2006,1117(2):163-169
A method for direct determination of DL-tetrahydropalmatine (DL-THP) in Corydalis yanhusuo, a traditional Chinese herb, by L-THP imprinted monolithic precolumn on-line/off-line coupling with reversed-phase high performance liquid chromatography (RP-HPLC) was developed. The L-THP imprinted monolithic column has been prepared by in situ polymerization using methacrylic acid (MAA) and ethylene dimethacrylate (EDMA) as functional monomer and cross-linker, respectively. With the optimization of chromatographic conditions, such as mobile phase composition, flow rate, column temperature and sample loading, for the separation of enantiomer, DL-THP was base-line separated on the MIP. The imprinted monolithic column was used as a precolumn for fractionation of the C. yanhusuo extract. Both the non-retained and retained fractions were separated by RP-HPLC. Meanwhile, the D-THP and L-THP can be detected in the non-retained and retained fractions, respectively. Additionally, direct determination of L-THP using molecularly imprinted monolith on-line coupling with a reversed-phase column was acquired.  相似文献   

13.
贾泽慧  王春涛  李华 《应用化学》2013,30(3):329-334
采用光谱相关色谱法对延胡索药材指纹图谱中的有效组分延胡索乙素峰进行确认;利用多元曲线分辨-交替最小二乘法(MCR-ALS)对延胡索乙素重叠峰簇进行解析,得到延胡索乙素的真实色谱峰,其光谱还原率大于0.999,并对其进行准确定量,该方法可作为指纹图谱的辅助方法,为中药的真伪鉴定和质量客观评价提供可靠依据;最后讨论了药材的炮制对延胡索乙素含量的影响。  相似文献   

14.
Bioactivity-guided fractionation of Corydalis yanhusuo has resulted in the isolation of eight known isoquinoline alkaloids - tetrahydropalmatine, isocorypalmine, stylopine, corydaline, columbamine, coptisin, 13-methylpalmatine, and dehydrocorybulbine. The tertiary alkaloids were further analyzed by chiral HPLC to determine the ratios of d-and l-isomers. The isolated compounds were screened for their binding affinities at the dopamine D(1) receptor. Isocorypalmine had the highest affinity (K(i) = 83 nM). The structure-affinity relationships of these alkaloids are discussed.  相似文献   

15.
Ca and/or F-modified fluorite-like Ce-Zr-mixed oxides have been prepared by Pechinis method. The bulk structure of samples was characterized by XRD, EXAFS and FTIRS of the lattice modes. The surface properties were studied by SIMS and FTIRS of adsorbed CO and surface hydroxyls. The specific reactivity of the surface oxygen, its amount, coefficients of bulk and near-surface diffusion, as dependent upon the sample composition and temperature, were estimated using sample reduction by CO in the pulse/flow mode. Insertion of fluorine into the lattice results in decreasing the degree of oxygen polyhedra distortion, thus decreasing the amount of reactive oxygen and diffusion coefficients. Calcium and Pt addition counteracts this effect. At 500oC for Pt-supported Ce-Zr-O samples including those modified by Ca and F, the lattice oxygen is easily removed by methane generating CO and hydrogen with high selectivity. Reoxidation of reduced samples by water or carbon dioxide at the same temperature restores the oxygen capacity producing more hydrogen or carbon monoxide.  相似文献   

16.
This study presents a novel and rapid method to identify chemical markers for the quality control of Radix Aconiti Preparata, a world widely used traditional herbal medicine. In the method, the samples with a fast extraction procedure were analyzed using direct analysis in real time mass spectrometry (DART MS) combined with multivariate data analysis. At present, the quality assessment approach of Radix Aconiti Preparata was based on the two processing methods recorded in Chinese Pharmacopoeia for the purpose of reducing the toxicity of Radix Aconiti and ensuring its clinical therapeutic efficacy. In order to ensure the safety and effectivity in clinical use, the processing degree of Radix Aconiti should be well controlled and assessed. In the paper, hierarchical cluster analysis and principal component analysis were performed to evaluate the DART MS data of Radix Aconiti Preparata samples in different processing times. The results showed that the well processed Radix Aconiti Preparata, unqualified processed and the raw Radix Aconiti could be clustered reasonably corresponding to their constituents. The loading plot shows that the main chemical markers having the most influence on the discrimination amongst the qualified and unqualified samples were mainly some monoester diterpenoid aconitines and diester diterpenoid aconitines, i.e. benzoylmesaconine, hypaconitine, mesaconitine, neoline, benzoylhypaconine, benzoylaconine, fuziline, aconitine and 10-OH-mesaconitine. The established DART MS approach in combination with multivariate data analysis provides a very flexible and reliable method for quality assessment of toxic herbal medicine.  相似文献   

17.
近红外光谱法结合化学计量学方法用于茶油真伪鉴别分析   总被引:10,自引:0,他引:10  
采用近红外光谱透反射模式结合化学计量学方法对纯茶油进行真伪鉴别.收集并扫描了163个样品(合格97个,不合格66个),对样本进行光谱数据预处理优化及有效波段筛选.在5750~6000 cm-1波段处,光谱经过平滑,一阶导数以及自归一化后,采用无监督学习算法即主成分分析法(Principal component anal...  相似文献   

18.
从超市选购15种微波适用塑料食品保鲜膜或袋作为样品,应用EN 1186-13-2002和GB/T 5009.156-2003两种标准方法中所述方法对样品在存放脂肪类食品时其组分迁移至食品中的总量做了测定。试验中用橄榄油和正己烷作为模拟食品,GB/T标准方法的检测结果表明:15种样品均属合格产品,而EN标准方法的检测结果表明在此15种样品中有4种属不合格,其合格率为73.3%。为探究两种方法所得结果存在差异的原因,采用红外光谱法(IR)、差示扫描量热法(DSC)及热失重法(TG)3种测试方法对上述样品作进一步研究。结果发现不合格的样品中含填料较高。此外,EN标准方法中所采用的样品预处理条件与实际使用情况更为接近。  相似文献   

19.
We discuss the clustering of 234 environmental samples resulting from an extensive monitoring program concerning soil lead content, plant lead content, traffic density, and distance from the road at different sampling locations in former East Germany. Considering the structure of data and the unsatisfactory results obtained applying classical clustering and principal component analysis, it appeared evident that fuzzy clustering could be one of the best solutions. In the following order we used different fuzzy clustering algorithms, namely, the fuzzy c-means (FCM) algorithm, the Gustafson–Kessel (GK) algorithm, which may detect clusters of ellipsoidal shapes in data by introducing an adaptive distance norm for each cluster, and the fuzzy c-varieties (FCV) algorithm, which was developed for recognition of r-dimensional linear varieties in high-dimensional data (lines, planes or hyperplanes). Fuzzy clustering with convex combination of point prototypes and different multidimensional linear prototypes is also discussed and applied for the first time in analytical chemistry (environmetrics). The results obtained in this study show the advantages of the FCV and GK algorithms over the FCM algorithm. The performance of each algorithm is illustrated by graphs and evaluated by the values of some conventional cluster validity indices. The values of the validity indices are in very good agreement with the quality of the clustering results. Figure Projection of all samples on the plane defined by the membership degrees to cluster A2, and A4 obtained using Fuzzy c-varieties (FCV) algorithm (expression of objective function and distance enclosed)  相似文献   

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