五味子超临界CO2提取物的气相色谱-质谱分析

将五味子样品于25 MPa、45 ℃下用超临界CO2提取2 h,提取物经气相色谱-质谱分析,共测得16个成分,经与对照品、NIST谱库对照和结构解析,鉴定出其中的7种木脂素成分,占色谱峰总面积的80.5%,其中五味子甲素9.39%、五味子乙素30.58%、五味子醇甲16.00%、五味子丙素5.95%和五味子醇乙15.17%。     

南北五味子醇提液的荧光光谱鉴别

建立了用荧光光谱法快速鉴别五味子和部分含五味子制剂中五味子药材种属的方法. 研究了五味子中的五味子醇甲、五味子酯甲、五味子甲素、五味子乙素和安五脂素5种活性成分以及南北五味子和护肝片的乙醇提取液的荧光光谱,并用高效液相色谱测定了供试品中5种活性成分的含量. 结果表明,安五脂素和五味子乙素具有强荧光性且峰形差异显著,五味子甲素和五味子醇甲的荧光性较弱,而五味子酯甲不具有荧光性;南北五味子的主要荧光物质分别为安五脂素和五味子乙素,据此可用乙醇提取液的荧光光谱快速鉴别南北五味子.     

超高效液相色谱-质谱法测定醋五味子中7种木脂素的含量北大核心CSCD

采用超高效液相色谱-质谱法测定醋五味子中五味子酯甲、五味子酚、五味子甲素、五味子乙素、五味子丙素、五味子醇甲和五味子醇乙等7种木脂素的含量。醋五味子样品0.200 0g用甲醇10mL超声提取30min。以ACQUITY UPLC BEH C_(18)色谱柱为分离柱,以不同体积比的乙腈和0.1%(体积分数)甲酸溶液的混合液为流动相进行梯度洗脱,质谱分析中采用电喷雾正离子源和选择离子监测模式。7种木脂素的质量浓度在一定范围内与其对应的峰面积呈线性关系,方法的检出限(3S/N)为0.001~0.050mg·L^(-1)。对6.0mg·L^(-1)的7种木脂素混合标准溶液连续测定6次,测定值的相对标准偏差为1.2%~3.5%。方法用于醋五味子样品的分析,加标回收率为85.4%~99.3%。     

超高效液相色谱-质谱法测定醋五味子中7种木脂素的含量

采用超高效液相色谱-质谱法测定醋五味子中五味子酯甲、五味子酚、五味子甲素、五味子乙素、五味子丙素、五味子醇甲和五味子醇乙等7种木脂素的含量。醋五味子样品0.200 0g用甲醇10mL超声提取30min。以ACQUITY UPLC BEH C_(18)色谱柱为分离柱,以不同体积比的乙腈和0.1%(体积分数)甲酸溶液的混合液为流动相进行梯度洗脱,质谱分析中采用电喷雾正离子源和选择离子监测模式。7种木脂素的质量浓度在一定范围内与其对应的峰面积呈线性关系,方法的检出限(3S/N)为0.001~0.050mg·L~(-1)。对6.0mg·L~(-1)的7种木脂素混合标准溶液连续测定6次,测定值的相对标准偏差为1.2%~3.5%。方法用于醋五味子样品的分析,加标回收率为85.4%~99.3%。     

南北五味子荧光光谱差异的原因

建立了用荧光法快速鉴别五味子和部分含五味子制剂中五味子是属于北五味子还是南五味子的方法,探明了南北五味子荧光光谱差异的主要原因。研究了五味子的五种活性成分五味子醇甲、五味子酯甲、五味子甲素、五味子乙素和安五脂素的荧光性质和五味子以及护肝片乙醇提取液的荧光光谱,并用高效液相色谱测定了供试品五种活性成分的含量。研究表明：发光效率按安五脂素、五味子乙素、五味子甲素和五味子醇甲依次减弱,五味子酯甲不具有荧光性;北五味子的主要荧光物质为五味子乙素,而南五味子的主要荧光物质是安五脂素,它们是导致南北五味子荧光光谱差异的主要原因。用荧光法鉴别南北五味子具有简单、快速和灵敏的特点     

高效液相色谱法测定北五味子中5种木脂素含量

应用高效液相色谱法测定北五味子中五味子醇甲、五味子酯甲、五味子甲素、五味子乙素和五味子丙素等5种木脂素的含量。北五味子样品(1.000g)在70℃温度下用甲醇(20mL)微波辅助提取5min。分取部分提取液,以Hypersil ODS C18色谱柱为固定相,用乙腈和水以不同比例混合的溶液为流动相进行梯度洗脱,在检测波长225nm处进行测定。5种木脂素在一定的质量浓度范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.029 2~0.050 7mg·L-1之间。以样品为基体,在3个浓度水平加入混合标准溶液进行回收试验,测得回收率在95.3%~101%之间,测定值的相对标准偏差(n=6)在1.1%~2.4%之间。     

一测多评高效液相色谱法同时测定五味子中五味子醇甲、五味子甲素、五味子乙素

建立一测多评高效液相色谱法同时测定五味子中五味子醇甲、五味子甲素、五味子乙素含量的方法,并验证该法的可行性和准确度。通过Plackett-Burman设计考察流动相中甲醇比例、流动相流量、柱温、进样体积对五味子醇甲色谱峰分离度的影响,确定流动相中甲醇比例、柱温为关键分析参数（P<0.05）。通过中心组合设计优化关键分析参数,建立色谱分析条件：以甲醇-水（体积比为70∶30）溶液作为流动相进行洗脱,流量为1.0 mL/min,柱温为35℃,检测波长为254 nm,进样体积为10μL。以五味子醇甲为内参物,分别建立五味子甲素、五味子乙素与五味子醇甲的相对校正因子,计算各成分含量,实现一测多评。采用外标法测定五味子甲素、五味子乙素含量,比较外标法的实测值与一测多评法预测值之间的差异,以验证一测多评法的准确度及可行性。五味子中五味子醇甲与五味子甲素、五味子乙素的相对校正因子分别为1.039、1.246。五味子醇甲、五味子甲素、五味子乙素色谱峰面积与质量浓度在5～500μg/mL范围内呈良好的线性关系,相关系数均大于0.999。样品加标回收率分别为100.1%、100.6%、100.3%,...     

基质固相分散萃取-高效液相色谱法同时测定五味子中5种木脂素类化合物北大核心CSCD

研究建立了基质固相分散萃取-高效液相色谱(MSPD-HPLC)分析五味子中5种木脂素类化合物(五味子醇甲、五味子醇乙、五味子甲素、五味子乙素、五味子丙素)的方法。采用反相C_(18)色谱柱进行分离,以0.1%(v/v)甲酸水溶液和乙腈为流动相进行梯度洗脱,在波长250 nm下检测。考察了包括硅胶、酸性氧化铝、中性氧化铝、碱性氧化铝、佛罗里硅土、Diol、XAmide、Xion和C_(18)、C_(18)-ME、C_(18)-G_(1)、C_(18)-HC等在内的12种吸附剂以及吸附剂的质量、洗脱剂的种类、洗脱剂体积对五味子木脂素类化合物得率的影响。选定Xion作为MSPD-HPLC分析五味子中木脂素类化合物的吸附剂;基于吸附剂Xion的萃取参数优化结果表明:以0.25 g五味子粉末为固定值,Xion(0.75 g)为吸附剂,甲醇(15 mL)为洗脱剂,MSPD对五味子中木脂素类化合物具有较高的得率。建立的五味子中5种木脂素类化合物的分析方法,各目标分析物具有良好的线性关系(相关系数R^(2)≥0.9999),检出限与定量限分别介于0.0089~0.0294μg/mL和0.0267~0.0882μg/mL之间。对五味子木脂素类化合物进行低、中、高3个水平的加标回收试验,平均回收率为92.2%~111.2%,相对标准偏差为0.23%~3.54%。日内和日间精密度均小于3.6%。与超声辅助提取和热回流提取前处理相比,MSPD具有萃取和净化相结合、耗时少、所需溶剂量少的优点,且MSPD-HPLC获得的结果优于经典方法。所建立的方法成功应用于17批五味子中5种木脂素类化合物含量的分析。     

目标因子分光光度法同时测定中成药复方五味子中三项活性成分

将目标因子分光光度法应用于五味子提取液中五味子甲素、五味子乙素、五味子醇甲等三项活性成分的同时测定,介绍了基本原理和具体的分析步骤,运用计算机VC 语言对试验数据进行回归分析。试验结果表明,目标因子分光光度法对样品各组分的平均回收率在98.9%-106.7%之间,样品不经分离即可同时测定。     

高效液相色谱法测定五味子和含五味子的制剂中五味子乙素及多种活性成分时流动相体系的选择

建立了用高效液相色谱法测定五味子和含五味子的制剂中五味子乙素的流动相体系。用Shim-pack VP-ODS (250 mm×4.6 mm,5 μm)色谱柱,在柱温30 ℃、检测波长285 nm、流速1.0 mL/min的条件下,用不同的流动相组成及其不同比例研究了五味子提取液中3种木脂素(五味子乙素、安五脂素和五味子甲素)的保留时间及其分离情况,从中选择测定五味子乙素的最佳流动相体系。结果表明,在甲醇-水、甲醇-冰醋酸-水的流动相体系中,安五脂素和五味子乙素很难完全分离;而在乙腈-甲醇-水和乙腈-冰醋酸-水流动相体系中,3种木脂素可很好地分离。以乙腈-甲醇-水(体积比为17:58:25)为流动相测定五味子和护肝片中3种木脂素的含量,相对标准偏差(n4)为0.95%～5.8%,平均加标回收率为94.50%～105.6%。将该流动相体系用于供试品中3种木脂素含量的测定,分离效果好,结果令人满意。     

Comprehensive quality evaluation of Fructus Schisandrae using electrospray ionization ion trap multiple-stage tandem mass spectrometry coupled with chemical pattern recognition techniques

Electrospray ionization ion trap multiple-stage tandem mass spectrometry (ESI-MS(n)) was used to evaluate Fructus Schisandrae of similar species (Schisandra chinensis (Turcz.) Baill. fruits and Schisandra sphenanthera Rehd. et Wils. fruits) and different growth characteristics (color, shape, etc.). The application of chemical pattern recognition in the ESI-MS(n) data analysis was carried out by principal component analysis (PCA), hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA). Then the antioxidant activity of different Fructus Schisandrae samples were determined by an LC-ESI-MS method and ferric reducing antioxidant power (FRAP) assay. Using the ESI-MS(n) method coupled with chemical pattern recognition analysis and correlated with the antioxidant activity evaluation, the two similar species were successfully distinguished, thus improving the therapeutic safety and effectiveness. The superior characteristics of Schisandra chinensis (Turcz.) Baill. fruits were obtained and made the selection and breeding of Chinese medicine materials more scientific. This study indicates that ESI-MS(n) is a valuable tool for the authentication of botanical origin and can also be useful for the quality control of Chinese medicinal herbs.     

Diagnosis of lung cancer based on metal contents in serum and hair using multivariate statistical methods

The classification of normal and cancer groups with four multivariate methods according to metal contents in serum and hair samples has been discussed in the present paper. Results show that the four multivariate methods, stepwise discrimination analysis, principal components analysis, hierarchical cluster analysis, and stepwise cluster analysis can distinguish the two groups correctly. The independent samples of both normal and cancer groups were tested and can be distinguished correctly by the four methods. Therefore, these methods can be used as an aid for diagnosis of lung cancer according to the metal contents in serum and hair samples.     

Discrimination of the Traditional Chinese Medicine from Schisandra Fruits by Flash Evaporation-Gas Chromatography/Mass Spectrometry and Fingerprint Analysis

Flash evaporation-gas chromatography/mass spectrometry (FE-GC/MS) with 0.3 mg sample powder in a vertical microfurnace pyrolyzer at 300 °C was applied to analyze Schisandra fruits without any tedious pretreatment. In total, 80 compounds, 74 compounds of which were identified, were observed, including low-molecular-weight compounds, essential oils (especially terpenoids), fatty acids and esters, and lignans, with the relative standard deviations (RSDs) of the relative percent of peak areas less than 7.79 % (n = 5). 32 compounds of terpenoids and lignans were selected as fingerprint components, since they are the main bioactive constituents in Schisandra fruits. The standard characteristic fingerprints of S. chinensis fruits and S. sphenantherae fruits were established, based on the 32 fingerprint components of 11 genuine S. chinensis fruit samples and 9 genuine S. sphenantherae fruit samples. The discrimination of samples from different growing places was achieved by principle component analysis and hierarchical cluster analysis. Furthermore, a similarity evaluation method was developed to evaluate the quality of each Schisandra fruit sample on the basis of the 32 fingerprint components. The results proved that the FE-GC fingerprint combined with a chemometric approach is a simple, rapid, and effective method for the origin discrimination and quality control of Schisandra fruits.

     

Analysis of Cnidium monnieri fruits in different regions of China

Application of multivariate data analysis has become a popular method in the last decades, mainly because it can provide information not otherwise accessible. The information includes classification, searching similarities, finding relationships, finding physical significance to principal components, etc. Fifty three Chinese medicinal herbs of eleven kinds of coumarins were collected and determined by HPLC. The results were studied by principal component analysis (PCA) and cluster analysis. It was showed that the samples could be clustered reasonably into different groups, which correspond with variation of regularity and distribution of coumarin of Cnidium monnieri fruits in different regions of China.     

中红外光谱技术应用于蜂蜜掺假预判的研究

由于蜂蜜蜜种多,成分复杂,加之蜂蜜掺假方式繁多,采用传统的方式很难对蜂蜜进行快速准确的鉴别。通过对国内多个地区的蜂蜜进行调研,采集来自全国20个省份多个蜜种的蜂蜜,利用中红外光谱仪对样品进行光谱扫描,采用主成分分析和聚类分析的方法,利用化学计量软件进行模型的建立。该识别模型不仅能较准确地判别蜂蜜是否掺假(准确率为95.36%),还能对添加量在10%以上的掺假方式进行预判,判别准确率为97.78%,符合判别模型的建立要求。利用中红外光谱技术对蜂蜜掺假进行鉴别的方法有效、可行。     

硅烷化GC-MS指纹图谱在卷烟品牌分析中的应用

采用硅烷化衍生化法结合气相色谱-质谱(GC-MS)法对卷烟烟丝中的主要化学成分进行检测,获得了21个卷烟样品的烟丝硅烷化GC-MS指纹图谱数据,并应用聚类分析和主成分分析法对烟丝硅烷化GC-MS指纹图谱数据进行综合评价。结果表明,该方法可用于不同品牌卷烟的比较和区分,硅烷化成分的含量分布特征能反映不同品牌卷烟的特性,可为卷烟品牌的风格表征、品质维护和真伪鉴别提供参考。     

Quantitative Determination of Lignan Constituents from Schisandra chinensis by Liquid Chromatography

The fruits of Schisandra chinensis (Schisandraceae/Magnoliaceae) are a traditional oriental medicine possessing diverse biological activities. A simple and specific analytical method for the quantitative determination of eight lignan constituents from the methanolic extract of the fruits of Schisandra chinensis was developed. The lignan constituents present in the fruits of Schisandra chinensis were separated with an acetonitrile-water-reagent alcohol gradient at a flow rate of 1.0 mL per minute. The HPLC separation was performed on a Phenomenex Luna C18 (2) (150 × 4.6 mm I.D., particle size 5 μm) reversed phase column with detection at 215 nm. The limit of detection was in the range from 0.2 to1.5 μg mL^?1. The relative standard deviation (RSD) values for the determination of lignan constituents in fruits of Schisandra chinensis were less than 2.0%. The method was successfully used to analyze different products available in the market containing Schisandra chinensis and also to study the percentage compositions of various lignans present in Schisandra chinensis procured from different regions in S. Korea.     

LF-NMR结合化学模式识别鉴别油脂种类及餐饮废弃油脂

应用主成分分析(Principal component analysis,PCA)和聚类分析法(Cluster analysis,CA)对9种(27个)常见食用植物油及100个餐饮废油的低场核磁共振(Low-field nuclear magnetic resonance,LF-NMR)(T2)弛豫特性数据进行分析。结果表明:在正常食用油种类区分方面,主成分分析的效果较优,9种食用油在主成分分布图上按种类正确分组,边界清晰。而在正常食用油与餐饮废油的区分方面,聚类分析效果较优,引入30个待测样本后,聚类分析(127个样品,欧式距离=5)的正确率为94.49%,分析误判率为5.51%,分组效果良好。LF-NMR结合化学模式识别可实现对油脂种类及餐饮废弃油脂的鉴别。     

UHPLC-TOFMS coupled with chemometric method as a powerful technique for rapid exploring of differentiating components between two Ziziphus species

To rapidly explore the differentiating components and the potential chemical markers for discrimination between those Chinese medicinal herbs with similar chemical characteristics, an ultra-high-performance liquid chromatography (UHPLC)-TOFMS coupled with multivariate statistical analysis method was proposed and validated by using two Ziziphus species (Z. jujuba and Z. jujuba var. spinosa) as the model herbs. After the samples were analyzed using UHPLC-TOFMS, the data sets of retention time (RT)-m/z pairs, ion intensities and sample codes were further processed with orthogonal partial least squared discriminant analysis (OPLS-DA) to holistically compare the difference between the fruits of these two Ziziphus species, and to generate an S-plot. Those compounds correlating to the points at the two ends of "S" were regarded as the most differentiating components between these two kinds of samples. By comparing the mass/UV spectra and retention times with those of reference compounds, these components were finally characterized as zizyberenalic acid, palmitoleic acid, oleic acid, pomonic acid and rutin, and these compounds would be the potential chemical markers for discrimination of these jujube products. The results suggested that this newly established approach could be used to rapidly determine the subtle differences and explore the potential chemical markers for differentiation within the herbs with similar chemical ingredients.     

Feasibility study on the use of infrared spectroscopy for the direct authentication of Iberian pig fattening diet

The feasibility of using both middle- and near-infrared spectroscopy for discrimination between subcutaneous fat of Iberian pigs reared on different fattening diets has been evaluated. The sample set was formed by subcutaneous fat of pigs fattened outdoors (extensively) with natural resources (montanera) and pigs fattened on commercial feeds, either with standard feed or with especial formulations with higher content in oleic acid (HO-formulated feed). Linear discriminant analysis was used to classify the samples according to the fattening diet using the scores obtained from principal component analysis of near- and middle-infrared spectra as variables to construct the discriminant functions. The most influential variables were identified using a stepwise procedure. The discriminant potential of each spectral region was investigated. Best results were obtained with the combination of both regions with 91.7% of the standard feed and 100% of montanera and HO-formulated feed samples correctly classified. Chemical explanations are provided based on the correlation of these variables with fatty acid content in the samples.