Qualitative and Quantitative Analysis of Alkaloids in Cortex Phellodendri by HPLC-ESI-MS/MS and HPLC-DAD

A combined method of high performance liquid chromatograph-elecrtrospray-ionization mass spectrometer（HPLC-ESI-MS/MS） coupled with a photodiode array detector（HPLC-DAD） and principal component analysis（PCA） was applied to the qualitative and quantitative analyses of alkaloids in Cortex Phellodendri（CP） samples, and to the differentiation of two species of CP, Cortex Phellodendri Chinensis（CPC） and Cortex Phellodendri Amurensis（CPA）. Twenty-two peaks appeared in the HPLC-MS base peak chromatogram of CP detected by the HPLC-ESI-MS/MS analysis, and the alkaloids were identified according to the MSn data, the known MS fragmentation rules and the literature data. Five alkaloids including berberine, palmatine, jatrorrhizine, phellodendrine and magnoflorine were simultaneously determinated by the HPLC-DAD. Berberine was the primary component in all CP samples, and the contents of berberine and palmatine were exploited to be two critical parameters for effective discrimination between the two species of CP. The average content of berberine in CPC（58.75 mg/g） was higher than that in CPA（9.16 mg/g）, while the content of palmatine was less, only 0.25 mg/g in CPC and 4.19 mg/g in CPA. With the use of PCA, samples datasets were separated successfully into two different clusters corresponding to the two species, and berberine, pahnatine, phellodendrine and magnoflorine contribute most to the above mentioned calssifying . The proposed method oroved to be a useful tool in the aualitv control of Chinese herbal medicines.

Qualitative and semi-quantitative analysis of health-care pharmaceutical products using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy(LIBS) is a sensitive optical technique that is capable of rapid multi-elemental analysis. The development of this technique for elemental analysis of pharmaceutical products may eventually revolutionize the field of human health. Under normal circumstances, the elemental analysis of pharmaceutical products based on chemical methods is time-consuming and complicated. In this investigation, the principal aim is to develop an LIBS-based methodology for elemental analysis of pharmaceutical products. This LIBS technique was utilized for qualitative as well as quantitative analysis of the elements present in Ca-based tablets. All the elements present in the tablets were detected and their percentage compositions were verified in a single shot, using the proposed instrument. These elements(e.g., Ca, Mg, Fe, Zn, and others) were identified by the wavelengths of their spectral lines, which were verified using the NIST database. The approximate amount of each element was determined based on their observed peaks and the result was in exact agreement with the content specification. The determination of the composition of prescription drug for patients is highly important in numerous circumstances. For example, the exploitation of LIBS may facilitate elemental decomposition of medicines to determine the accuracy of the stated composition information. Moreover, the approach can provide element-specific, meaningful, and accurate information related to pharmaceutical products.

Qualitative and Quantitative Analysis of Linoleic Acid in Polygonati Rhizoma

Objective To explore the major compound in Polygonati Rhizoma(Huang Jing,黄精)for quality control.Methods The major compound was isolated and analyzed by liquid chromatography-mass spectrometry(LC-MS),and subsequently further identified by nuclear magnetic resonance(NMR).Thin layer chromatography(TLC)was optimized based on the previous methods reported in the Chinese Pharmacopeia(2015 edition).Results The major compound was isolated from the natural material and identified as linoleic acid.A high performance liquid chromatography(HPLC)method with robust linearity(R2=0.9997),specificity,precision,stability,repeatability and recovery was developed for linoleic acid determination.TLC chromatogram was improved significantly after optimization for qualitative analysis.Conclusions The optimized TLC method is practical and can be adopted for quality control of Polygonati Rhizoma(Huang Jing,黄精).The levels of linoleic acid vary between species of Polygonati Rhizoma(Huang Jing,黄精),with Polygonatum cyrtonema Hua(Jiang Xing Huang Jing,姜型黄精)showing the highest contents.This study provides valuable information for quality control of Polygonati Rhizoma(Huang Jing,黄精).

Consequences of Insufficient Selectivity in Quantitative and Qualitative Chemical Analysis

A problem in chemical analysis in connection with measurements of a substance normally occurring in a sample, or identification of a substance which should not exist in a sample, is insufficient selectivity. In this article, we analyze this problem and propose remedies. We use a real doping case to illustrate how chemical noise causes a serious selectivity problem, probably causing a false positive outcome.

The research of mine rock burst hazard identification based on fault tree analysis

In order to identify the rock burst hazard in coalmine and thus to give a credible forecast, firstly, analyzed such effect factors as natural geological factors and mining technological conditions based on the investigation of more than one hundred mine rock burst cases. Secondly, adopted the fault tree analysis （FTA） technology to the mine rock burst hazard identification for the first time and confirmed twelve kinds of basic events, that is, the large mining depth, the burst-orientation coal seams, the solid strata of roof and bottom, near the faults with bigger fall, the folds, the change of seam thickness, other regional tectonics transformation or stress strip, the drilling, blasting and extracting operation, the unscientific extracting methods, the illogical extracting sequence, the residual pillars and the too close distance between the working face and the residual areas or the stopping extracting lines. Moreover, worked out the fault tree of mine rock burst. At last, it made qualitative analysis and quantitative analysis and forecasted the rock burst hazard according to the characteristic of geologic structure and exploitation technology conditions in certain mine of Shandong Province, China, the rock burst accidents happened in the following exploitation validated that it is of feasibility and veracity adopting FTA to identify the mine rock burst hazard.

Advantages and Disadvantages of Quantitative and Qualitative Information Risk Approaches

Due to rapidly development of information systems, risk and security issues have increased and became a phenomenon that concerns every organization, without considering the size of it. To achieve desired results, managers have to implement methods of evaluating and mitigating risk as part of a process well elaborated. Security risk management helps managers to better control the business practices and improve the business process. An effective risk management process is based on a successful IT security program. This doesn＇t mean that the main goal of an organization＇s risk management process is to protect its IT assets, but to protect the organization and its ability to perform their missions. During this process, managers have to take into consideration risks that can affect the organization and apply the most suitable measures to minimize their impact. The most important task is choosing the best suited method for analyzing the existing risk properly. Several methods have been developed, being classified in quantitative and qualitative approaches of evaluating risk. The purpose of this paper is to present the advantages and disadvantages of each approach taking current needs and opportunities into consideration.

On Improving Students＇ Listening Proficiency From Correlation Analysis Between English Listening and Other English Skills

Researches have proved that in human beings＇ actual languange communication, listening is the most important part. However, in English learning, listening seems always to be a weakness for many Chinese students. English learning is a systematic process, during which, English listening proficience is influeced by many factors. Therefore, from the systematicness and inner relations in English learning and based on qualitative analysis and quantitative analysis between English listening and other English skills in English listening, this paper tries to give the correlation analysis and accordingly give some suggestions to improve listening proficiency for ESL （English as a second language） learners

Qualitative and quantitative analysis of four different polarity fractions from Huang-Lian-Jie-Du-Decoction by HPLC-DAD-ESI-MS/MS and their related neuroprotective effects

Huang-Lian-Jie-Du-Decoction （HLJDD） has been widely used for the treatment of Alzheimer＇s disease （AD） in clinic. However, the relationship between its chemical profile and neuroprotective bioactivity was not clearly clarified yet. In present study, the water extract of HLJDD and subsequent three polarity fractions divided by different reagents were investigated. A total of 17 chromatographic peaks were confirmed by comparison with standards and their UV, MS spectra. Among them, 11 major compounds were determined by HPLC-DAD method with good linear regression relationship （r2, 0.9994-0.9999）, precisions （inter-day precision RSD, 0.79%-1.07%; intra-day precision RSD, 1.59%-2.10%）, repeatability （RSD, 1.66%-3.67%）, stability （RSD, 1.26%-4.77%） and recovery （95.24%-105.41%, RSD, 0.29%-2.69%）. Furthermore, PC12 cells and primary neurons cells were used for the neuroprotective effective assessment of aforementioned four samples from HLJDD. 3＂he total aqueous extract and n-butanol extract of HLJDD presented more significant effects than the other two parts. According to their quality and quantity determination results, iridoids and alkaloids have a positive correlation with the neuroprotective effectiveness of HLJDD.

Qualitative and quantitative analysis ofβ-sitosterol marker in virgin camellia oil and virgin olive oil

Camellia oil and olive oil with superior economic value are easily adulterated with other,cheaper oils.It is difficult to identify both oils by traditional methods because of their similar fatty acid profiles.In the present study,a novel method for qualitative and quantitative analysis ofβ-sitosterol using GC/MS and GC/FID was developed to identify camellia oil and olive oil.The method validation ofβ-sitosterol analysis showed good linearity and satisfactory values for recovery,accuracy,precision,and repeatability.The linear regression coefficient(R^(2))of the calibration curve was 0.9985.An acceptable limit of detection(0.36 mg/100 g)and limit of quantification(1.20 mg/100 g)were achieved.The spiked recoveries were 95.0%to 100.3%.The relative standard deviation(RSD)of within-day precision was less than 3.26%,and the RSD of retention times and peak areas for repeatability were within 0.03%and 1.08%,respectively.The contents ofβ-sitosterol in virgin camellia oil and virgin olive oil were in the range of 14.1–30.2 mg/100 g and 94.3–173.2 mg/100 g,respectively,indicating that theβ-sitosterol content in the former is seven times that in the latter,andβ-sitosterol could be a potential marker for the authentication and adulteration detection of both oils.

Qualitative and quantitative analysis of atmospheric methanol using a continuous-wave terahertz spectrometer

We present a specific-window method to subtract the interference of water vapor on terahertz frequency-domain spectroscopy（THz-FDS） at ambient temperature and pressure. A continuous-wave spectrometer based on photomixing was utilized to obtain THz-FDS of methanol vapor in the range of 50–1200 GHz. The distinctly spaced absorption features in the neighborhood of atmospheric windows of transparency were selected to perform linear fitting versus the calculated absorption cross section and obtain the concentration of methanol. Furthermore, the gradually decreased methanol vapor was quantified to demonstrate the reliability of the method.

寒地杏种质资源果实性状评价及优异鲜食资源筛选

以29份寒地杏种质资源为试材,测定果实23个质量性状和6个数量性状并进行分析评价,以期为深入了解寒地杏种质资源遗传多样性、挖掘和高效利用杏资源提供参考依据。结果表明:29份资源数量性状中果实硬度和单果质量变异系数最大,分别为68.35%和40.32%,单果质量和核鲜质量呈显著正相关;质量性状的多样性指数变化范围为0.2732~1.6731,果形多样性指数最高,为1.6731,风味和果实颜色的多样性指数分别为1.2049和1.1919,说明杏资源表型多样性较为丰富;主成分分析表明前8个主成分能代表23个描述型性状的大部分信息,累计方差贡献率达77.789%;筛选出6份优异鲜食杏资源,分别为‘丹麦黄杏’‘双山杏’‘桦甸杏’‘白杏1’‘九台晚杏’‘桦甸红杏’。

基于故障树分析的通用无人飞行器武控系统典型案例研究

针对通用无人飞行器武控系统结构复杂、难于建立精确数学模型等特点,利用故障树分析法,以“网络接口发送正常,接收异常”、“武控台显示对接训练弹加电查询异常”、“武控电源操控面板上指示灯不亮”等典型故障为例,详细描述故障现象,深入剖析故障原因,全面梳理故障机理,精准建立故障树,标准表达故障格式;依据专家经验,给出故障的出现率及对武控系统的影响程度,完成故障定性定量分析,从而更高效地实现该故障的定位和排除,同时可为维修保障过程中出现的各种故障提供完整的故障诊断案例借鉴;因此,具有一定的理论和实用价值,为后续该型无人飞行器武器装备提供系统、全面、针对性和时效性强的作战使用技术保障产品打下坚实的基础,进而全面提升该型无人飞行器武器装备使用和维修保障能力。

X射线荧光光谱在国内航空金属材料分析中的应用

该文介绍了X射线荧光光谱分析(XRF)的基本原理及其进行定性分析、半定量分析、定量分析的理论基础。对检测涉及的基体效应、光谱重叠等影响因素及数学校正方法进行了简单说明。总结了航空用金属材料中铝合金、镁合金、钛合金、钢铁、高温合金、陶瓷、金属基复合材料、镀层分析以及手持荧光定性、半定量快速分析近年来在航空金属材料分析中的应用情况,梳理了XRF分析的技术要点并对XRF技术的发展进行了展望。

吸热燃料裂解产物分析及裂解过程推测

采用全二维气相色谱-质谱联用仪(GC×GC-MS/FID)和便携式微型气相色谱仪对类JP-7吸热型碳氢燃料高温裂解气液相产物进行定性定量分析,并根据分析结果研究了裂解过程。分析结果表明,气相产物主要为氢气、甲烷、乙烯、乙烷和丙烯,较低裂解温度下的裂解液相产物主要为未裂解的原料及低分子量的链烯烃、环烯烃等不饱和烃和烷基苯类及茚类;680~700℃,裂解产物中低分子量的不饱和烃含量出现了转折,此时芳烃含量开始急剧增加;组分含量的变化表明裂解过程首先是小分子气体及低分子量烯烃的产生,其次随着裂解温度的提高,低分子量烯烃含量增加的同时又部分转化产生了芳烃的过程。

管理研究中的质性元分析方法:适用问题、操作策略与应用展望

以往管理领域的元分析研究重点关注定量元分析方法的使用,导致众多质性研究结论未得到有效的整理与提炼,而质性元分析作为对质性研究进行整合的方法,能够有效解决以往管理质性研究之间存在的孤岛现象,旨在构建一般性的管理理论。鉴于此,首先,介绍了质性元分析方法的内涵、认识论基础和相较其他研究方法的优势。在此基础上,回顾以往研究,归纳总结了该方法目前的应用现状,包括适用的研究问题和规范的操作策略。最后,从问题、操作和方法3个方面提出了未来管理研究中质性元分析方法的应用前景。

不同种类道路沥青材料异味特征及析源分析

随着我国社会经济逐渐向绿色可持续转型,沥青路面铺筑过程中的异味污染成为不可忽视的环境问题。本研究针对八种不同的道路沥青材料使用过程中产生的挥发性物质,通过气相色谱-质谱联用仪(GC-MS)和气体检测仪进行定性与定量分析。在此基础上,结合异味阈值计算各物质异味活度值(OAV),通过异味活度值加和(SOAV)的方法对沥青异味进行分析,并对异味污染物中各组分及其异味贡献进行进一步的析源工作。研究结果表明,沥青挥发物的浓度与异味活度值加和并没有完全的正相关关系,胶粉改性沥青挥发物浓度及异味活度值加和相较于其他沥青均有显著提高。对八种不同种类道路沥青材料异味特征进行分析得出:六种组分对沥青异味的产生有贡献,其中,苯系物、醛类以及硫化氢对沥青异味的贡献较大,烯烃类以及酮类是胶粉改性沥青挥发物中特有的异味贡献组分。

拉曼光谱结合化学计量学方法的复方柳安咖注射液成分分析

为了实现复方柳安咖注射液成分的快速检测,利用拉曼光谱的指纹识别性、聚焦式采样方法及水影响较低的特点结合化学计量学方法对复方柳安咖注射液进行了分析。复方柳安咖注射液针剂样品的拉曼光谱显示,复方柳安咖注射液针剂的拉曼光谱主要由水杨酸钠、安替比林和咖啡因的水溶液拉曼谱带组成。以水杨酸钠梯度溶液拉曼光谱特征峰812 cm^(-1)和1033 cm^(-1)、安替比林梯度溶液拉曼光谱特征峰724 cm^(-1)和1005 cm^(-1),依据散射光强与相应组分浓度之间的关系,利用光谱特征峰高度、峰面积分别建立定量分析模型;考虑各成分光谱间的相互干扰,也利用水杨酸钠梯度溶液光谱745~920 cm^(-1)、1010~1060 cm^(-1)波段数据和安替比林梯度溶液拉曼光谱700~750 cm^(-1)、950~1020 cm^(-1)波段数据,基于偏最小二乘法(PLS)建立定量分析模型。两种分析模型对三个不同厂家不同生产批次的31个针剂样品中主要成分水杨酸钠和安替比林的含量进行预测,预测值与液相色谱法测试值相近;预测水杨酸钠和安替比林含量分别为标示量的96.4%~102.3%之间和98.1%~105.8%之间,都符合国家药品标准,与液相色谱测试法的分析结果一致。表明拉曼光谱结合化学计量学方法能对复方柳安咖注射液成分进行定量分析,具有准确、方便、快捷的优点。

外语教材使用实证研究方法评析与展望

本文首先对实证研究方法进行概述,包括实证研究方法的分类以及不同方法的特征及其适用范围,然后使用范围综述的方法,检索并筛选出近年来有关外语教材使用实证研究的SSCI和CSSCI来源期刊文章,对其进行评析。结果表明,国内外研究都以定性研究为主,国外位居第二的是混合研究,而国内是定量研究,近年来混合研究逐渐增加。本文进一步选取两个案例详细分析其采用的研究方法、数据收集与分析过程、研究结果以及对教学实践的指导意义,为后续研究提供借鉴。文章最后指出当前外语教材使用实证研究方法存在的不足,并提出了相应的改进措施,同时展望了未来研究趋势,以期引导后续研究的方向,并推动外语教材使用研究的深入发展。

网络安全风险评估方法研究综述

网络安全风险评估是构建网络空间安全体系的重要环节,可以有效保护个人和组织机构避免受到网络安全攻击。文中简要概述了网络安全风险评估理论,重点介绍了目前主流的网络安全风险评估方法,并根据不同的方法性质对现有方法进行分类和对比,分析了各方法的优缺点以及适用范围。在此基础上,文中归纳提取出对网络安全评估结果产生影响的因素并对网络安全评估领域未来的研究重点进行提议。分析结果表明,关联性和评估指标的不确定性以及评估过程的实时性这3个因素是影响风险评估效果的主要因素,并给未来的风险评估方法研究提供了参考依据。

中药怀牛膝醇提物有效单体成分的定性定量研究

目的:基于现代检测技术对怀牛膝有效制剂——牛膝醇提物的单体成分进行定性定量分析。方法:将怀牛膝醇提物液体制剂按照检测进样要求分别制备成烘干物和液体物,再应用核磁共振波谱(Nuclear Magnetic Resonance,NMR)、气相色谱质谱联用(Gas Chromatography-Mass Spectrometry,GC-MS)、顶空-气相色谱质谱联用(Headspace-Gas Chromatography-Mass Spectrometry,HS-GCMS)、液相色谱质谱联用(Liquid Chromatography-Mass Spectrometry,LC-MS)、三重串联四极杆液相质谱联用(Triple Series Quadrupole Liquid Mass Spectrometry,LC-MSMS)等技术对牛膝醇提物的化学成分进行鉴定分析。结果:共检测出23个单体成分,包括糖类1个,类黄酮类1个,黄酮类1个,甾酮类1个,三萜类1个,氨基酸类16个,果酸类2个,其中槲皮素含量为0.0021%,β-蜕皮甾酮含量为0.0210%,齐墩果酸含量为0.00017%,并根据分子片段信息预测出了4’,5,6,7-四甲氧基黄酮成分。结论:本实验为怀牛膝醇提物制剂的临床应用提供了有效单体成分参考,为进一步对其单体物质的“药物-疾病-靶点”进行验证研究和开发应用提供依据。