期刊文献+
共找到2,828篇文章
< 1 2 142 >
每页显示 20 50 100
Secondary metabolite credentials ofEvolvulus alsinoides by high performance thin layer chromatography(HPTLC) 被引量:2
1
作者 Duraisamy Gomathi Manokaran Kalaiselvi +3 位作者 Ganesan Ravikumar Dominic Sophia Velliyur Kanniappan Gopalakrishnan Chandrasekar Uma 《The Journal of Biomedical Research》 CAS 2012年第4期295-302,共8页
Plants and plant-based products are the bases of many modern pharmaceuticals that are current in use today for various diseases.The aim of the study was to investigate the biochemical constituents and high performance... Plants and plant-based products are the bases of many modern pharmaceuticals that are current in use today for various diseases.The aim of the study was to investigate the biochemical constituents and high performance thin layer chromatography(HPTLC) finger printing of the ethanolic extract of Evolvulus alsinoides.Phytochemical screening was done by standard procedures and HPTLC method was also established to analyze alkaloids,flavonoids and phenolic compounds from the ethanolic extract of Evolvulus alsinoides.Preliminary phytochemical screening showed that ethanol extracted more secondary metabolites than other solvents.HPTLC fingerprinting analysis showed the presence of various alkaloids,flavonoids and phenols(quercetin) in the ethanolic extract.It can be concluded that Evolvulus alsinoides may serve as a source of potent antioxidants that may be used in the prevention of various diseases such as cancer,diabetes and cardiovascular diseases due to the presence of phenolic compounds.HPTLC finger print of Evolvulus alsinoides may be useful in the differentiation of the species from adulterants and act as a biochemical marker for this medicinally important plant in the pharmaceutical industry and plant systematic studies. 展开更多
关键词 Evolvulus alsinoides high performance thin layer chromatography(HPTLC) secondary metabolites CONVOLVULACEAE
下载PDF
Comparison of liquid-liquid extraction-thin layer chromatography with solid-phase extraction-high-performance thin layer chromatography in detection of urinary morphine 被引量:1
2
作者 Ali Ahadi Alireza Partoazar +1 位作者 Mohammad Hassan Abedi Khorasgani Seyed Vahid Shetab Boushehri 《The Journal of Biomedical Research》 CAS 2011年第5期362-367,共6页
Liquid-liquid extraction-thin layer chromatography (LLE-TLC) has been a common and routine combined method for detection of drugs in biological materials. Solid-phase extraction (SPE) is gradually replacing the tr... Liquid-liquid extraction-thin layer chromatography (LLE-TLC) has been a common and routine combined method for detection of drugs in biological materials. Solid-phase extraction (SPE) is gradually replacing the tra- ditional LLE method. High performance thin layer chromatography (HPTLC) has several advantages over TLC. The present work studied the higher efficiency of a new SPE-HPTLC method over that of a routine LLE-TLC method, in extraction and detection of urinary morphine. Fifty-eight urine samples, primarily identified as mor- phine-positive samples by a strip test, 'were re-screened by LLE-TLC and SPE-HPTLC. The results of LLE-TLC and SPE-HPTLC were then compared with each other. The results showed that the SPE-HPTLC detected 74% of total samples as morphine-positive samples whereas the LLE-TLC detected 48% of the same samples. We further discussed the effect of codeine abuse on TLC analysis of urinary morphine. Regarding the importance of morphine detection in urine, the present combined SPE-HPTLC method is suggested as a replacement method for detection of urinary morphine by many reference laboratories. 展开更多
关键词 morphine detection liquid-liquid extraction thin-layer chromatography solid-phase extraction highperformance thin layer chromatography
下载PDF
Evaluation of quantitative variation of secondary metabolites in Bergenia ciliata(Haw.)using high performance thin layer chromatography 被引量:1
3
作者 Nishi Srivastava Sharad Srivastava +2 位作者 Shikhar Verma Ajay Kumar Singh Rawat Abdul Rahman Khan 《The Journal of Biomedical Research》 CAS 2014年第4期328-331,共4页
Dear Editor: Therapeutically active metabolite contents in a med- icinal plant vary in nature, which may impact on its therapeutic efficacy. Bergenia (Saxifragaceae) is an evergreen perennial herb widely distribut... Dear Editor: Therapeutically active metabolite contents in a med- icinal plant vary in nature, which may impact on its therapeutic efficacy. Bergenia (Saxifragaceae) is an evergreen perennial herb widely distributed in Central and East Asia with about 30 species reported worldwide. It grows at a range of altitudes from the Khasia hills at 400 feet to the temperate Himalayas from Kashmir to Bhutan at 7,000-10,000 feet. Its distribution over a wide range of altitudinal zones makes it a good candidate for studying variations in its metabolic profiles under different climatic conditions. Bergenin (C-glycoside of 4-O-methyl gallic acid) has been identified as a potent active secondary metabolite in Bergenia and other therapeutically active constituents including, among others, gallic acid (3,4,5 trihydroxybenzoic acid), (+) catechin, and gallicin (Fig. 1). 展开更多
关键词 HPTLC using high performance thin layer chromatography Evaluation of quantitative variation of secondary metabolites in Bergenia ciliata Haw HIGH
下载PDF
Study of Cuscuta chinensis Lam. in Nuhuang Fuzheng Oral Liquid by Thin Layer Chromatography
4
作者 Wengui FU Zhiqiang YAN +3 位作者 Shaoqin ZHAI Maixun ZHU Hua ZHENG Xingzhong SUN 《Medicinal Plant》 CAS 2017年第5期6-10,共5页
[Objectives] To better control the quality of Nuhuang Fuzheng Oral Liquid and study the main component Cuscuta chinensis Lam.by Thin Layer Chromatography. [Methods] Through changing the treatment methods of the test s... [Objectives] To better control the quality of Nuhuang Fuzheng Oral Liquid and study the main component Cuscuta chinensis Lam.by Thin Layer Chromatography. [Methods] Through changing the treatment methods of the test sample solution,proportion of the developing solvent and sample application volume,taking the spot resolution,definition,and Rf value,optimal Thin Layer Chromatography conditions were screened for Cuscuta chinensis Lam. [Results] After the test sample solution passing the neutral alumina column,it was extracted two times using the ethyl acetate. Methanol was added to dissolve. Benzene-ethyl acetate-formic acid( 5∶5∶2.5) was used as developing solvent.And ammonia fumigation was carried out to develop color. In the thin layer chromatograph obtained through these conditions,Nuhuang Fuzheng Oral Liquid test sample solution showed the same stripe in the same position of the control drug chromatogram and there was no obvious tailing phenomenon and the spot was clear. [Conclusions] The thin layer chromatography identification conditions can be used as the method for quality control of Cuscuta chinensis Lam. in Nuhuang Fuzheng Oral Liquid. 展开更多
关键词 Nuhuang Fuzheng Oral Liquid Identification by thin layer chromatography CUSCUTA CHINENSIS LAM Quality control
下载PDF
Application of Thin Layer Chromatography in Preparation of Drug Containing Serum of Eucalyptus Oil
5
作者 Bingyang GUO Yongli YU +2 位作者 Shijuan LUO Xiaoqing YIN Mingzhen XU 《Medicinal Plant》 CAS 2018年第1期19-24,共6页
[Objectives] To explore whether the thin layer chromatography( TLC) can be used to guide the preparation of drug containing serum of eucalyptus oil. [Methods]Eucalyptus oil samples with different dilution ratio were d... [Objectives] To explore whether the thin layer chromatography( TLC) can be used to guide the preparation of drug containing serum of eucalyptus oil. [Methods]Eucalyptus oil samples with different dilution ratio were detected by TLC. Eucalyptus oil was intragastrically administered to mice,serum samples of different eucalyptus oil doses,different intragastric administration methods and different blood sampling times were collected. The above samples were detected by TLC,and the above results were verified by gas chromatography. [Results] TLC can detect concentration difference of eucalyptus oil samples with different dilution ratio. TLC can provide qualitative and semi-quantitative detection of eucalyptus oil in serum. High,medium and low dose of eucalyptus oil in serum had different effects on the growth of MCF-7 cells in the SD rats( P < 0. 05). [Conclusions] TLC can be used to guide the preparation of drug containing serum of eucalyptus oil. 展开更多
关键词 Chinese medicine drug containing serum Eucalyptus oil thin layer chromatography
下载PDF
DETERMINING THE CONTENT OF JASMINODIN IN MEI RONG CAPSULE WITH THIN LAYER CHROMATOGRAPHY
6
作者 慕慧 李林 +2 位作者 周玲 王晓利 胡森科 《Academic Journal of Xi'an Jiaotong University》 2001年第1期81-82,共2页
Objective Jasminodin in Mei Rong capsule was determined by the method or thin layer chromatog- raphy. Mothods The sample Jasminodin was extracted with methanol and then the extract was chromatographed on silica gel GF... Objective Jasminodin in Mei Rong capsule was determined by the method or thin layer chromatog- raphy. Mothods The sample Jasminodin was extracted with methanol and then the extract was chromatographed on silica gel GF254 plate with chloroform-methanol-water(10:3:1) as mobile phase and the chromatograms were scanned by using Shimadzu CS-930 dual wavelength TLCS in zegzag scanning mode at λ_s 370nm and λR 250nm. Results Callbration graph was rectilinear between 2.7μg^16.2μg per spot for the jasminodin. Conclusion Satisfa- tory results were obtained with the average recovery ratio of 99.76%,RSD 2.27%. 展开更多
关键词 jasminodin thin layer chromatography Mei Rong capsule
下载PDF
Identification of Ethnic Medicine Polygonum capitatum by Thin Layer Chromatography
7
作者 Haicheng WEN Yongjing SU +2 位作者 Huagang LIU Wei WEI Songji WEI 《Medicinal Plant》 CAS 2022年第2期16-17,共2页
[Objectives]To establish a thin-layer chromatography identification method for the ethnic medicinal materials of Polygonum capitatum.[Methods]The thin layer chromatography(TLC)method was used to identify materials.[Re... [Objectives]To establish a thin-layer chromatography identification method for the ethnic medicinal materials of Polygonum capitatum.[Methods]The thin layer chromatography(TLC)method was used to identify materials.[Results]The TLC identification showed that in the chromatogram of the test sample,there were spots of the same color in the corresponding position of the chromatogram of the reference medicinal material,and the reproducibility was good.[Conclusions]The TLC identification and the determination results of the inspection items can provide a basis for the quality control of the medicinal materials of P.capitatum. 展开更多
关键词 Ethnic medicine Polygonum capitatum thin layer chromatography(TLC) Quality control
下载PDF
Preparation Process and Thin Layer Chromatography Identification of Wufang Babu Poultice
8
作者 Junjun LIU Luyao XIE +2 位作者 Chuhui ZHOU Zhengteng YANG Xiongbin GUI 《Medicinal Plant》 CAS 2023年第4期58-61,共4页
[Objectives] To establish the process flow of preparation of Wufang Babu Poultice and the identification method of thin layer chromatography (TLC). [Methods] For the forming process of Wufang Babu Poultice, the prepar... [Objectives] To establish the process flow of preparation of Wufang Babu Poultice and the identification method of thin layer chromatography (TLC). [Methods] For the forming process of Wufang Babu Poultice, the preparation method of mixed pharmaceutical powder with suitable pharmaceutical excipients was adopted. Qualitative identification of medicinal materials in Wufang Babu Poultice (Strychni Semen, Rhei Radix Et Rhizoma, Dipsaci Radix, and Angelicae Sinensis Radix) was carried out by TLC. [Results] Mixed pharmaceutical powder mixed with glycerol, gelatin and other pharmaceutical excipients can be prepared for forming. The test solution chromatography of each medicinal material (Strychni Semen, Rhei Radix et Rhizoma, Dipsaci Radix, Angelicae Sinensis Radix) showed pigment spots of the same color at the same position as its corresponding control medicinal materials and reference chromatography, and the display was clear. [Conclusions] The preparation process is simple and feasible, and can be used as the forming process of Wufang Babu Poultice. The TLC determination method is simple to operate, has good specificity, and has no effect on negative results, and can be used for identification of Wufang Babu Poultice. 展开更多
关键词 Wufang Babu Poultice Preparation process thin layer chromatography(TLC)
下载PDF
Identification of Citric Acid in Wuhuang Oral Liquid by Thin Layer Chromatography
9
作者 Zhiqiang YAN Guowen CAO +2 位作者 Shaoqin ZHAI Maixun ZHU Hua ZHENG 《Medicinal Plant》 2017年第3期43-46,共4页
[Objectives] To screen the identification conditions of citric acid in Wuhuang Oral Liquid by thin layer chromatography,and establish the quality control method for citric acid in Wuhuang Oral Liquid.[Methods] Differe... [Objectives] To screen the identification conditions of citric acid in Wuhuang Oral Liquid by thin layer chromatography,and establish the quality control method for citric acid in Wuhuang Oral Liquid.[Methods] Different treatment methods were adopted for test sample,developing agent,and drying time,thin layer chromatography separation condition and spot definition were taken as indicators to conduct experiment,to select optimal thin layer identification method. [Results] Methanol was used as the extraction solvent,ultrasonic treatment,ether extraction,dissolution by anhydrous ethanol as treatment conditions of test sample; upper solution of butyl acetate-formic acid-water(4 ∶ 2 ∶ 2) after placing one hour was taken as developing agent; 0. 1% bromocresol green(BCG) as the developer; when developing the color in 3 hours after development,in thin layer chromatograph,there appeared the same strip in the same position of test sample of Wuhuang ORAL Liquid and control substance,no obvious trailing phenomenon,and the color was uniform and clear.[Conclusions]The thin layer chromatography identification conditions can be used as the method for quality control of Wuhuang Oral Liquid. 展开更多
关键词 Wuhuang ORAL LIQUID IDENTIFICATION by thin layer chromatography Quality control
下载PDF
Algerian mint species:high performance thin layer chromatography quantitative determination of rosmarinic acid and in vitro inhibitory effects on linoleic acid peroxidation
10
作者 Brahmi Fatiha Madani Khodir +2 位作者 Stévigny Caroline Chibane Mohamed Duez Pierre 《Journal of Coastal Life Medicine》 2014年第12期986-992,共7页
Objective:To determine the quantitative paremeters of rosmarinic acid in Algerian mints,Mentha spicata L.(M.spicata),Mentha pulegium L.and Mentha rotundifolia(L.)Huds by high performance thin layer chromatography(HPTL... Objective:To determine the quantitative paremeters of rosmarinic acid in Algerian mints,Mentha spicata L.(M.spicata),Mentha pulegium L.and Mentha rotundifolia(L.)Huds by high performance thin layer chromatography(HPTLC)-densitometric method and screen the effects of these plant extracts on linoleic acid peroxidation.Methods:The analyses were performed on HPTLC silica gel 60 F254 plates with chloroform:acetone:formic acid(75:16.5:8.5,v/v)as the mobile phase.Rosmarinic acid was determined in UV at 365 nm and fluorescence at λ_(exc)325 nm with a 550 nm filter,respectively.The effects of plants extracts on linoleic acid peroxidation were measured by an indirect in vitro colorimetric method.Results:Chromatographic resolution permitted reliable quantification in both measurement modes and calibration curves were linear in a range of 150-1000 ng/spot.M.spicata was found to contain significantly higher concentrations of rosmarinic acid.The densitometric quantification allowed the analysis of many samples in a short time with reasonable precision(total precision for Mentha spp extracts,5.1%and 5.8%for UV and fluorescence detection,respectively).The HPTLC data,allied to assays of linoleic acid peroxidation prevention,suggested the potential of M.spicata(52%Trolox®equivalents)as a natural source for inhibitors of lipid peroxidation.Conclusions:Densitometry can be used for routine determination and quality control of rosmarinic acid in herbal and formulations containing Mentha species. 展开更多
关键词 DENSITOMETRY High performance thin layer chromatography Lipid peroxidation Mentha sp Rosmarinic acid
原文传递
Separation and Detection of Ceramides by HPLC Followed by Evaporative Light-Scattering Detection and Thin Layer Chromatography
11
作者 张琳 周全 +1 位作者 傅学奇 陈国强 《Tsinghua Science and Technology》 SCIE EI CAS 2002年第6期660-664,共5页
Ceramides are important signaling molecules involved in a variety of cellular processes, including cell growth, differentiation, and apoptosis. Currently, different methods are used for ceramide analysis, some of whic... Ceramides are important signaling molecules involved in a variety of cellular processes, including cell growth, differentiation, and apoptosis. Currently, different methods are used for ceramide analysis, some of which are insensitive or cumbersome. This paper described methods utilizing thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) followed by evaporative light scattering detection (ELSD) to detect ceramide directly in cell extracts without derivatization, which was proved to be efficient and reproducible. Five kinds of ceramides were used as standards. Both TLC and normal-phase HPLC/ELSD results indicate that yeast contains several kinds of ceramides. 展开更多
关键词 CERAMIDE SPHINGOLIPID ERGOSTEROL thin layer chromatography (TLC) high-performance liquid chromatography (HPLC) evaporative light scattering detection (ELSD)
原文传递
Thin Layer Chromatography and Methodological Investigation of Matrine in Zhukuqin Granule
12
作者 Wei WEI Wenjie ZHONG +1 位作者 Juan LIU Rongbin LING 《Medicinal Plant》 2017年第2期4-7,共4页
[Objectives] To establish a sensitive and simple thin layer chromatography method of matrine in Zhukuqin granule. [Methods]With Zhukuqin granule as control medicinal materials,matrine as reference substance,we chose o... [Objectives] To establish a sensitive and simple thin layer chromatography method of matrine in Zhukuqin granule. [Methods]With Zhukuqin granule as control medicinal materials,matrine as reference substance,we chose orthogonal test method,systematically investigated various factors affecting the thin layer chromatography,and selected the best thin layer chromatography conditions. [Results] We screened out the best thin layer chromatography of matrine in the Zhukuqin granule with chloroform as extraction solvent,solvent extraction and ultrasonic extraction as extraction method,toluene-acetone-ethyl acetate-ammonia solution( 2:3:4:0. 5) as developing agent,improvement of bismuth potassium iodide solution as color developing agent. [Conclusions] The separating degree of this method was high,it had good repeatability,and it could be used to control quality of Zhukuqin granule. 展开更多
关键词 Zhukuqin GRANULE MATRINE thin layer chromatography
下载PDF
Thin Layer Chromatography Screening for Glycyrrhiza uralensis
13
作者 Lijing CAO Lihua YUAN Kaiyan LIAO 《Medicinal Plant》 2017年第4期32-36,共5页
[Objectives] To establish a simple and rapid,specific and reproducible thin layer chromatography( TLC) method,and accordingly establish a thin layer identification method for quality control of Glycyrrhiza uralensis. ... [Objectives] To establish a simple and rapid,specific and reproducible thin layer chromatography( TLC) method,and accordingly establish a thin layer identification method for quality control of Glycyrrhiza uralensis. [Methods] According to the physical and chemical properties,components of Glycyrrhiza uralensis were identified by thin layer chromatography. According to Veterinary Pharmacopoeia of the People's Republic of China 2010( Volume Ⅱ) and related literature report,the thin layer chromatography identification method was studied and improved for Glycyrrhiza uralensis.[Results] When the preparation method for test sample solution was 6g Glycyrrhiza uralensis added with 30 mL saturated n-butanol,ultrasonic processing 20 min,filtered,filtrate dried,added 3 mL methanol and obtained Glycyrrhiza uralensis test sample solution. Then,chloroform-methanol-formic acid-ethyl acetate( 10∶ 3∶ 2∶ 3) as developing solvent,clear spot with high degree of separation and reproducibility could be obtained,and can be used for thin layer chromatography identification of ammonium glycyrrhetate in Glycyrrhiza uralensis.[Conclusions] The modified method omitted the step of ether treatment of samples,and directly adopted saturated n-butanol to extract components. It does not influence the detection of chromatographic spots,and solves the issue of sample gelatinizing sticking and filtration,simplifies the test process,and reduces the harm to human body. 展开更多
关键词 GLYCYRRHIZA uralensis SEPARATION effect thin layer chromatography identification Developing SOLVENT
下载PDF
Quality Evaluation of Leontopodium franchetii Beauv. from Different Localities Based on Moisture,Ash and Extract Contents and Thin-layer Chromatography
14
作者 Pei QUN Yatao HAN +3 位作者 Fang XIAO Zhe LIU Yongxia KE Yuan LIU 《Medicinal Plant》 CAS 2018年第4期56-58,共3页
[Objectives] The aim was to determine the moisture,ash and extract contents in Leontopodium franchetii Beauv. from different localities. [Methods] The contents of moisture,total ash,acid-insoluble ash and extract in L... [Objectives] The aim was to determine the moisture,ash and extract contents in Leontopodium franchetii Beauv. from different localities. [Methods] The contents of moisture,total ash,acid-insoluble ash and extract in L. franchetii from different localities were determined according to the methods described in Chinese Pharmacopoeia( 2015 Edition). [Results] In the 10 samples,the contents of moisture were all less than or equal to 15. 0%; the contents of total ash were all below 12. 0%; and the contents of acid-insoluble ash were all less than 3. 0%. The contents of water-soluble extract( by cold-soaked extraction method) in the samples were all below 12. 0% except those from Hongyuan Prairie of Sichuan Province and Xinglong Mountain in Lanzhou City,Gansu Province. [Conclusions]The contents of the four indicators measured in this experiment varied by small margins,indicating that the quality was relatively stable. This study provides theoretical data for the revision of the quality standards for L. franchetii. 展开更多
关键词 Leontopodium franchetii Beauv. MOISTURE ASH Extract Content thin-layer chromatography Quality evaluation
下载PDF
Separation of Amino Acids Based on Thin-Layer Chromatography by a Novel Quinazoline Based Anti-Microbial Agent
15
作者 Supriti Sen Sandipan Sarkar +1 位作者 Pijush Kundu Subrata Laskar 《American Journal of Analytical Chemistry》 2012年第9期669-674,共6页
A newly designed quinazoline based compound, 6-pyridin-2-yl-5,6-dihydro-benzo[4,5]imidazo[1,2-c] quinazoline (PDBIQ) has shown the ability for the easy detection of nineteen amino acids on thin-layer chromatography pl... A newly designed quinazoline based compound, 6-pyridin-2-yl-5,6-dihydro-benzo[4,5]imidazo[1,2-c] quinazoline (PDBIQ) has shown the ability for the easy detection of nineteen amino acids on thin-layer chromatography plates as a spray reagent. This new reagent enabled to produce various distinguishable colors with amino acids with different RF values. The detection limits and the binding ability of PDBIQ with amino acids have been calculated. PDBIQ is also able to detect aminoacids from hydrolised seed protein. The title compound also exhibited profound inhibitory action against some gm (+ve) and gm (-ve) bacterial organisms. This paper deals with synthesis, spectroscopic application and biological evaluation of the organic moity. 展开更多
关键词 thin-layer chromatography Amino Acid NINHYDRIN Binding Constant ANTIMICROBIAL Property
下载PDF
Optimizing the nickel boride layer thickness in a spectroelectrochemical ATR-FTIR thin-film flow cell applied in glycerol oxidation 被引量:2
16
作者 Steffen Cychy Sebastian Lechler +7 位作者 Zijian Huang Michael Braun Ann Cathrin Brix Peter Blümler Corina Andronescu Friederike Schmid Wolfgang Schuhmann Martin Muhler 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第12期2206-2215,共10页
The influence of the drop-casted nickel boride catalyst loading on glassy carbon electrodes was investigated in a spectroelectrochemical ATR-FTIR thin-film flow cell applied in alkaline glycerol electrooxidation.The c... The influence of the drop-casted nickel boride catalyst loading on glassy carbon electrodes was investigated in a spectroelectrochemical ATR-FTIR thin-film flow cell applied in alkaline glycerol electrooxidation.The continuously operated radial flow cell consisted of a borehole electrode positioned 50μm above an internal reflection element enabling operando FTIR spectroscopy.It is identified as a suitable tool for facile and reproducible screening of electrocatalysts under well-defined conditions,additionally providing access to the selectivities in complex reaction networks such as glycerol oxidation.The fast product identification by ATR-IR spectroscopy was validated by the more time-consuming quantitative HPLC analysis of the pumped electrolyte.High degrees of glycerol conversion were achieved under the applied laminar flow conditions using 0.1 M glycerol and 1 M KOH in water and a flow rate of 5μL min^(–1).Conversion and selectivity were found to depend on the catalyst loading,which determined the catalyst layer thickness and roughness.The highest loading of 210μg cm^(–2)resulted in 73%conversion and a higher formate selectivity of almost 80%,which is ascribed to longer residence times in rougher films favoring readsorption and C–C bond scission.The lowest loading of 13μg cm^(–2)was sufficient to reach 63%conversion,a lower formate selectivity of 60%,and,correspondingly,higher selectivities of C_(2)species such as glycolate amounting to 8%.Thus,only low catalyst loadings resulting in very thin films in the fewμm thickness range are suitable for reliable catalyst screening. 展开更多
关键词 Catalyst layer thicknes ELECTROCATALYST Nickel boride Operando ATR-IR High performance liquid chromatography Flow cell thin film Anodic glycerol oxidation
下载PDF
Thin Layer Chromatographic Study of Bauxite and Quantitative Estimation of Co-Existing Al^(3+), Fe^(2+) and Ti^(4+)
17
作者 MOHAMED NAJAR P A JEURKAR J U RAMANA RAO K V 《色谱》 CAS CSCD 北大核心 2005年第5期555-561,共7页
Thin layer chromatography in combination with spectrophotometry and titrimetry has been used to evaluate chromatographic characteristics of bauxite constituents. The retention behaviors of four major constituents (Al... Thin layer chromatography in combination with spectrophotometry and titrimetry has been used to evaluate chromatographic characteristics of bauxite constituents. The retention behaviors of four major constituents (Al 3+ , Fe 2+ , Ti 4+ , Si 4+ ) in bauxite mineral have been examined on plain and modified layers of silica gel G, silica gel H and cellulose with mobile phases containing aqueous sodium chloride, formic acid and hydrochloric acid. Ternary separation of Al-Fe-Ti was achieved on chromatographic plates made of silica gel H. The pH effect and presence of impurity elements in samples, nature of stationary phases on the ternary separation and detection limits of bauxite constituents were studied. Silicon in bauxite was detected on cellulose plates. Quantitative determinations of Al 3+ , Fe 2+ and Ti 4+ on silica gel H impregnated with sodium formate layers were achieved by titrimetry and spectrophotometry. 展开更多
关键词 铝土矿 主成分 共存离子 Ti^4+ AL^3+ FE^2+ 薄层色谱法
下载PDF
Novelties Filtration Theory of Liquid Chromatography-Mass Spectrometry in Volume Nanotube of Cotton Filament of Layers Woven Fabrics
18
作者 ElSayed A. ElNashar 《Journal of Textile Science and Technology》 2021年第1期14-21,共8页
Objectives of the research to present a modern theory of water purification for multiple purposes entitled “a novelties filtration theory of liquid chromatography-mass spectrometry” is an exceedingly sensitive and s... Objectives of the research to present a modern theory of water purification for multiple purposes entitled “a novelties filtration theory of liquid chromatography-mass spectrometry” is an exceedingly sensitive and specific analytical technique in volume layers woven fabrics that can precisely determine the identities and quantities of compounds within volume Nanotube of cotton filament of layers woven fabrics. The problems are that the filters in the local and international markets have increased complications in configuration, installation and cost without reaching the efficiency that humanity hopes. Throw materials and methods the chromatography-mass spectrometry in layers woven fabrics, and throw the nanotube of cotton filament for purification of water dyes and smells. Industry, in which mass spectrometry is a convenient, versatile method for characterization and identification of process throw the Nanotube of cotton filament for purification of water dyes and smells. Results came up with a theme “innovations in textiles”, and also, for characterization of fibers and contaminants of the fabrics. Additive manufacturing in layers woven fabrics, are the processes used to synthesize a volume object under computer control with successive material layers that have been used and highlighted. The conclusions has included chromatography-mass spectrometry drop, physico-chemical, biological, combined physical-biological and chemical-biological treatment processes recently being developed to meet Jet-filtration, the strict discharging limits set by ASTM standards. Some important aspects of both qualitative and quantitative data analysis have been described and the power of using mass profiles to enhance selectivity and sensitivity has been demonstrated. 展开更多
关键词 Filtration Theory Liquid chromatography-Mass SPECTROMETRY layerS Woven Fabrics
下载PDF
基于Box-Behnken设计-响应面法优化调肝活血稳压颗粒提取工艺及其质量标准的研究
19
作者 李凡 张国松 +4 位作者 魏鑫华 贾超 夏明艳 李东勲 张文锍 《陕西中医药大学学报》 2025年第1期100-106,共7页
目的优化调肝活血稳压颗粒的提取工艺,并对其质量标准进行研究。方法本研究以浸膏得率及丹酚酸B的转移率的综合评分为指标,采用单因素考察结合Box-Behnken设计-响应面法优化调肝活血稳压颗粒的提取工艺,采用薄层色谱法对方中药材进行鉴... 目的优化调肝活血稳压颗粒的提取工艺,并对其质量标准进行研究。方法本研究以浸膏得率及丹酚酸B的转移率的综合评分为指标,采用单因素考察结合Box-Behnken设计-响应面法优化调肝活血稳压颗粒的提取工艺,采用薄层色谱法对方中药材进行鉴别。结果确定最终提取工艺为:第一次加入10倍量水煎煮90 min,第二次加入6倍量水煎煮60 min。测定方法结果准确可靠。薄层色谱法检测出天麻、栀子、丹参等三味中药的特征性斑点。结论优化后的提取工艺操作简单,提取效果良好,结果稳定可靠。 展开更多
关键词 调肝活血稳压颗粒 丹酚酸B 薄层色谱法 高效液相色谱法 Box-Behnken设计-响应面法
下载PDF
基于评价抽检的市售钩藤质量评价
20
作者 范秀春 彭晓丹 +2 位作者 胡建勇 李文锐 董坤 《医药导报》 CAS 北大核心 2025年第1期47-60,共14页
目的全面评价市售钩藤的质量。方法对29批钩藤进行法定标准(性状、鉴别、检查、浸出物)检验;使用薄层色谱(TLC)法对钩藤对照药材、毛钩藤碱、去氢毛钩藤碱、钩藤碱、异钩藤碱进行鉴别;使用高效液相色谱(HPLC)法建立钩藤特征图谱,采用聚... 目的全面评价市售钩藤的质量。方法对29批钩藤进行法定标准(性状、鉴别、检查、浸出物)检验;使用薄层色谱(TLC)法对钩藤对照药材、毛钩藤碱、去氢毛钩藤碱、钩藤碱、异钩藤碱进行鉴别;使用高效液相色谱(HPLC)法建立钩藤特征图谱,采用聚类分析、主成分分析(PCA)-X及正交偏最小二乘法判别分析(OPLS-DA)法对共有峰峰面积进行统计分析,筛选出钩藤的关键质量控制成分,同时测定钩藤中喜果苷、异去氢钩藤碱、去氢钩藤碱、异钩藤碱、钩藤碱、去氢毛钩藤碱、毛钩藤碱的含量,整体评价钩藤质量。结果29批样品中,合格样品23批,合格率79.31%;TLC法鉴别发现:不同基源钩藤化学成分差异较大,大叶钩藤未检出毛钩藤碱,华钩藤未检出去氢毛钩藤碱,毛钩藤未检出4种成分,仅基源为钩藤的样品在与对照药材和对照品色谱相应的位置上显相应的斑点;HPLC法测定结果表明:不同基源钩藤的化学成分及含量差异较大,大叶钩藤未检出去氢钩藤碱和毛钩藤碱,华钩藤未检出异去氢钩藤碱、去氢钩藤碱和去氢毛钩藤碱,毛钩藤仅检出喜果苷,且喜果苷含量较低。基于统计分析,不同批次钩藤间存在差异,并发现可能导致钩藤质量差异的3个已知关键质控成分:异去氢钩藤碱、去氢钩藤碱、异钩藤碱。结论钩藤整体质量不理想,现行炮制规范和检验标准无法确保产品质量,影响临床用药的安全性和有效性,不同基源钩藤的化学成分类别及含量差异较大,增加了制定统一质量标准的难度。 展开更多
关键词 钩藤 薄层色谱法 特征图谱 含量测定 模式识别 质量评价
下载PDF
上一页 1 2 142 下一页 到第
使用帮助 返回顶部