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Mechanism of Cinnamomum camphora essential oil for analgesia based on gas chromatography-mass spectrometry integrated network pharmacology
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作者 Nianyun Yang 《Asian Journal of Traditional Medicines》 2023年第3期87-97,共11页
This study aims to explore the analgesic ingredients and mechanism of Cinnamomum camphora essential oil(CCEO).The constituents in CCEO were characterized qualitatively by gas chromatography-mass spectrometry.Targets r... This study aims to explore the analgesic ingredients and mechanism of Cinnamomum camphora essential oil(CCEO).The constituents in CCEO were characterized qualitatively by gas chromatography-mass spectrometry.Targets related to active ingredients were collected by PubChem and Swiss Target Prediction.Targets related to pain were screened by TTD and OMIM database,and compound-target network was established by Cytoscape software.Gene ontology(GO)function and Kyoto encyclopedia of genes and genomes(KEGG)pathway enrichment analysis of targets were carried out by DAVID database.Protein-protein interaction(PPI)network was established and analyzed by STRING database.Molecular docking method was used to verify the interaction between main components and relevant core targets.A total of 13 compounds were identified in CCEO,and 58 related targets were predicted.GO function enrichment analysis revealed that the selected targets were mainly involved in biological processes such as chemical synaptic transmission and molecular function such as neurotransmitter receptor activity;24 signal pathways were screened by KEGG pathway enrichment analysis,including neuroactive ligand-receptor interaction,retrograde endocannabinoid signaling and calcium signaling pathway.Docking results showed that the main constituents had certain affinities with the key targets.The active ingredients in CCEO regulated multiple signaling pathways to ameliorate pain through AR,ACHE,ESR1,GABRG2,PTGS2 and PPARγ. 展开更多
关键词 Cinnamomum camphora essential oil gas chromatography-mass spectrometry ANALGESIC network pharmacology selina-6-en-4-ol
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Chemical profiling of bioactive compounds in the methanolic extract of wild leaf and callus of Vitex negundo using gas chromatographymass spectrometry
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作者 Gunjan Garg Alok Bharadwaj +1 位作者 Shweta Chaudhary Veena Gupta 《World Journal of Experimental Medicine》 2024年第1期78-87,共10页
BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.neg... BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.negundo),a perennial herb belonging to the Varbanaceae family,is extensively used in conventional medication.AIM To determine the existence of therapeutic components in leaf and callus extracts from wild V.negundo plants using gas chromatography-mass spectrometry(GCMS).METHODS In this study,we conducted GC-MS on wild plant leaf extracts and correlated the presence of constituents with those in callus extracts.Various growth regulators such as 6-benzylaminopurine(BAP),2,4-dichlorophenoxyacetic acid(2,4-D),α-naphthylacetic acid(NAA),and di-phenylurea(DPU)were added to plant leaves and in-vitro callus and grown on MS medium.RESULTS The results clearly indicated that the addition of BAP(2.0 mg/L),2,4-D(0.2 mg/mL),DPU(2.0 mg/L)and 2,4-D(0.2 mg/mL)in MS medium resulted in rapid callus development.The plant profile of Vitex extracts by GC-MS analysis showed that 24,10,and 14 bioactive constituents were detected in the methanolic extract of leaf,green callus and the methanolic extract of white loose callus,respectively.CONCLUSION Octadecadienoic acid,hexadecanoic acid and methyl ester were the major constituents in the leaf and callus methanolic extract.Octadecadienoic acid was the most common constituent in all samples.The maximum concentration of octadecadienoic acid in leaves,green callus and white loose callus was 21.93%,47.79%and 40.38%,respectively.These findings demonstrate that the concentration of octadecadienoic acid doubles in-vitro compared to in-vivo.In addition to octadecadienoic acid;butyric acid,benzene,1-methoxy-4-(1-propenyl),dospan,tridecanedialdehyde,methylcyclohexenylbutanol,chlorpyrifos,n-secondary terpene diester,anflunine and other important active compounds were also detected.All these components were only available in callus formed in-vitro.This study showed that the callus contained additional botanical characteristics compared with wild plants.Due to the presence of numerous bioactive compounds,the medical use of Vitex for various diseases has been accepted and the plant is considered an important source of therapeutics for research and development. 展开更多
关键词 Leaf extracts Callus extracts Methanolic extract Octadecadienoic acid Hexadecanoic acid Methyl ester gas chromatography-mass spectrometry analysis
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Simultaneous Determination of Hexoestrol, Diethylstilbestrol, Estrone and 17-Beta-estradiol in Feed by Gas Chromatography-mass Spectrometry 被引量:6
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作者 Huo Feng Li Ning Lin Xiao-Li 《Journal of Northeast Agricultural University(English Edition)》 CAS 2016年第1期44-49,共6页
A method was developed for the simultaneous determination of four kinds of estrogens (hexoestrol, diethylstilbestrol, estrone, and 17-beta-estradiol) in feed by gas chromatography-mass spectrometry (GC-MS). After ... A method was developed for the simultaneous determination of four kinds of estrogens (hexoestrol, diethylstilbestrol, estrone, and 17-beta-estradiol) in feed by gas chromatography-mass spectrometry (GC-MS). After the sample was extracted by ethyl ether and cleaned-up on HLB phase extraction column, four kinds of estrogens were derived and quantified in gas chromatographymass spectrometry. The results showed that the linear detectable ranged from 2.5 ng· mL-1 to 250 ng· mL-1for hexoestrol and from 5 ng· mL-1 to 500 ng· mL-1 for three other estrogens with the correlation coefficients (R2) were no less than 0.990. The recoveries were in the range of 76.34%-96.33% and the relative standard deviation was no more than 22.7%. The limits of quantitation (LOQ) for all analytics were between 10 ug· kg^-1 and 20 ug· kg^-1. The method was accurate and sensitive and could meet the actual requirements for the analyses of feed samples. 展开更多
关键词 gas chromatography-mass spectrometry hexoestrol DIETHYLSTILBESTROL ESTRONE 17-beta-estradiol FEED
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Comparative analysis of essential oils found in Rhizomes Curcumae and Radix Curcumae by gas chromatography-mass spectrometry 被引量:5
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作者 Di-Ya Lu Yan Cao +5 位作者 Ling Li Zhen-Yu Zhu Xin Dong Hai Zhang Yi-Feng Chai Zi-Yang Lou 《Journal of Pharmaceutical Analysis》 SCIE CAS 2011年第3期203-207,共5页
A comparison of the volatile compounds in Rhizomes Curcumae (Ezhu) and Radix Curcumae (Yujin) was undertaken using gas chromatography mass spectrometi-y (GC-MS). Ultrasonic extraction and GC-MS methods were deve... A comparison of the volatile compounds in Rhizomes Curcumae (Ezhu) and Radix Curcumae (Yujin) was undertaken using gas chromatography mass spectrometi-y (GC-MS). Ultrasonic extraction and GC-MS methods were developed for the simultaneous determination of five sesquiterpenes, namely, α-pinene, β-elemene, curcumol, germacrone and curdione, in Ezhu and Yunjin. Good linearity (r〉0.999) and high inter-day precision were observed over the investigated concentration ranges. The validated method was successfully used for the simultaneous determination of five sesquiterpenes in Ezhu and Yujin. The quantitative method can be effectively used to evaluate and monitor the quality of Chinese curcuma in clinical use. 展开更多
关键词 gas chromatography-mass spectrometry Rhizomes Curcumae Radix Curcumae Volatile compounds Quality control
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Volatile components of Rhizoma Alpiniae Officinarum using three different extraction methods combined with gas chromatography-mass spectrometry 被引量:3
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作者 Zhi-Sheng Xie Xin-Jun Xu +3 位作者 Chun-Yan Xie Jie-Yun Huang Mei Yang De-Po Yang 《Journal of Pharmaceutical Analysis》 SCIE CAS 2013年第3期215-220,共6页
Volatile components from Rhizoma Alpiniae Officinarum were respectively extracted by three methods including hydrodistillation, headspace solid-phase microextraction (HS-SPME) and diethyl ether extraction. A total o... Volatile components from Rhizoma Alpiniae Officinarum were respectively extracted by three methods including hydrodistillation, headspace solid-phase microextraction (HS-SPME) and diethyl ether extraction. A total of 40 (hydrodistillation), 32 (HS-SPME) and 37 (diethyl ether extraction) compounds were respectively identified by gas chromatography-mass spectrometry (GC/MS) and 22 compounds were overlapped, including β-farnesene, 7-muurolene, 2,6-dimethyl-6- (4-methyl-3-pentenyl)bicyclo[3.1.1]hept-2-ene, eucalyptol and cadina-1(10), 4-diene and so forth, varying in relative contents. HS-SPME is fast, sample saving and solvent-free and it also can achieve similar profiles as those from hydrodistillation and solvent extraction. Therefore, it can be the priority for extracting volatile components from medicinal plants. 展开更多
关键词 Rhizoma AlpiniaeOfficinarum Volatile components HYDRODISTILLATION Headspace solid-phasemicroextraction Diethyl ether extraction gas chromatography-mass spectrometry
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Metabolomic Fingerprint of the Model Ciliate, Tetrahymena thermophila Determined by Untargeted Profiling Using Gas Chromatography-Mass Spectrometry 被引量:1
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作者 XU Jing BO Tao +1 位作者 SONG Weibo WANG Wei 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第3期654-662,共9页
The ciliate Tetrahymena is a valuable model organism in the studies of ecotoxicology. Changes in intracellular metabolism are caused by exogenous chemicals in the environment. Intracellular metabolite changes signify ... The ciliate Tetrahymena is a valuable model organism in the studies of ecotoxicology. Changes in intracellular metabolism are caused by exogenous chemicals in the environment. Intracellular metabolite changes signify toxic effects and can be monitored by metabolomics analysis. In this work, a protocol for the GC-MS-based metabolomic analysis of Tetrahymena was established. Different extraction solvents showed divergent effects on the metabolomic analysis of Tetrahymena thermophila. The peak intensity of metabolites detected in the samples of extraction solvent Formula 1(F1) was the strongest and stable, while 61 metabolites were identified. Formula 1 showed an excellent extraction performance for carbohydrates. In the samples of extraction solvent Formula 2(F2), 66 metabolites were characterized, and fatty acid metabolites were extracted. Meanwhile, 57 and 58 metabolites were characterized in the extraction with Formula 3(F3) and Formula 4(F4), respectively. However, the peak intensity of the metabolites was low, and the metabolites were unstable. These results indicated that different extraction solvents substantially affected the detected coverage and peak intensity of intracellular metabolites. A total of 74 metabolites(19 amino acids, 11 organic acids, 2 inorganic acids, 11 fatty acids, 11 carbohydrates, 3 glycosides, 4 alcohols, 6 amines, and 7 other compounds) were identified in all experimental groups. Among these metabolites, amino acids, glycerol, myoinositol, and unsaturated fatty acids may become potential biomarkers of metabolite set enrichment analysis for detecting the ability of T. thermophila against environmental stresses. 展开更多
关键词 TETRAHYMENA THERMOPHILA metabolomics ECOTOXICOLOGY gas chromatography-mass spectrometry
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Multiresidue Method for Determination of 67 Pesticides in Water Samples Using Solid-Phase Extraction with Centrifugation and Gas Chromatography-Mass Spectrometry 被引量:3
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作者 Abir Kouzayha Abdul Rahman Rabaa +3 位作者 Mohamad Al Iskandarani Daniel Beh Hélène Budzinski Farouk Jaber 《American Journal of Analytical Chemistry》 2012年第3期257-265,共9页
A new multi-residue method based on solid-phase extraction (SPE) with centrifugation was developed for determination and quantitation of 67 pesticides in water samples. Two SPE cartridges were tested: Chromabond C18 a... A new multi-residue method based on solid-phase extraction (SPE) with centrifugation was developed for determination and quantitation of 67 pesticides in water samples. Two SPE cartridges were tested: Chromabond C18 and Oasis HLB. Parameters that influence the extraction efficiency such as the eluent volume, the sample loading volume, the addition of organic solvent to water sample, sorbent drying and elute concentration were optimized. The innovation of this work was the examination of the use of a centrifugation technique in both the drying and elution steps. When combined with centrifugation, the volume of the elution solvent was reduced to 2 mL and the time for sorbent drying decreased also to 10 min under vacuum. Under the optimized conditions, this method showed good recoveries higher than 65% - 68% for the 67 analyzed pesticides using the C18 and HLB cartridges with relative standard deviations lower than 9.7% - 12.3%. Limits of quantification were between 2 and 20 ng.L–1. The simplicity of the described method, use of less of organic solvent, short procedure time, and good recoveries demonstrate the advantages of this environmentally friendly approach for routine analysis of numerous samples. 展开更多
关键词 MULTI-RESIDUE PESTICIDES SOLID-PHASE Extraction CENTRIFUGATION gas chromatography-mass SPECTROMETRY
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Analysis of spectrum characteristics of optical scintillation in stack gas flow 被引量:1
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作者 刘文清 刘和来 +1 位作者 曾宗泳 江宇 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第8期1777-1782,共6页
Based on the analysis of spectrum characteristics of intensity fluctuations while light beams pass through stack gas flow in an industrial setting, this paper puts emphasis upon discussing the spectrum of optical inte... Based on the analysis of spectrum characteristics of intensity fluctuations while light beams pass through stack gas flow in an industrial setting, this paper puts emphasis upon discussing the spectrum of optical intensity fluctuations by the variety of particle concentration in stack gas flow. This paper also gives the primary theoretical explanation of the measurement results in the stack of coal-fired utility boilers. Meanwhile, the cross-correlation formula is given as the theoretical basis of velocity measurement by using particle concentration scintillation. 展开更多
关键词 stack gas flow optical scintillation particle concentration spectrum
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Gel Permeation Chromatography Purification and Gas Chromatography-Mass Spectrometry Detection of Multi-Pesticide Residues in Traditional Chinese Medicine 被引量:2
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作者 Wan-E Zhuang Zhen-Bin Gong 《American Journal of Analytical Chemistry》 2012年第1期24-32,共9页
The measurement of 23 organochlorine, organophosphorus, and pyrethroid pesticides in typical traditional Chinese medicine (TCM), flos lonicerae, was made using gel permeation chromatography (GPC) purification and gas ... The measurement of 23 organochlorine, organophosphorus, and pyrethroid pesticides in typical traditional Chinese medicine (TCM), flos lonicerae, was made using gel permeation chromatography (GPC) purification and gas chroma- tography-mass spectrometry (GC-MS) detection. The pesticides were extracted with ultrasonic device and 5.0 mL mixture of ethyl acetate and cyclohexane (1:1, v/v). Coextractants from sample matrices which may have interfere to the qualitative and quantitative analysis, such as pigments, were removed using GPC purification. Simultaneous full scan and selective ion monitor (scan/SIM) mode for GC-MS was used for qualitative and quantitative analysis, which pro- vided retention time and characteristic fragments ratio for each pesticide so as to positively identify each analyte. Rela- tive standard deviations (RSDs) were within 7.7% (5.0 - 22.5 μg/kg, n = 3). The recoveries of pesticide standards at the spiked concentration of 5.0 - 22.5 μg/kg were between 87.1% and 110.9%. Limits of detection (LODs) for the analytes were 0.16 - 3.2 μg/kg, which could meet the demand of routine analysis and TCM quality control. 展开更多
关键词 Traditional Chinese Medicine Multi-Pesticide RESIDUE Flos Lonicerae Gel PERMEATION CHROMATOGRAPHY gas chromatography-mass SPECTROMETRY
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Ultrasonic Nebulization Extraction Coupled with Gas Chromatography-Mass Spectrometry for Analysis of Volatile Components in Traditional Chinese Patent Medicine 被引量:1
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作者 LIANG Yue WANG Lu WANG Zi-ming YU Cui ZHANG Han-qi SHI Yu-hua 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2011年第2期203-207,共5页
The ultrasonic nebulization extraction(UNE) was developed and applied to the extraction of volatile components from traditional Chinese patent medicine Xiaoyao Pills. Several parameters of ultrasonic nebulization ex... The ultrasonic nebulization extraction(UNE) was developed and applied to the extraction of volatile components from traditional Chinese patent medicine Xiaoyao Pills. Several parameters of ultrasonic nebulization extraction including the sample particle size, solvent volume, extraction time and ultrasonic power were studied and selected. As a result, 2.4 g of sample with particle size of 80 mesh was extracted with 15 mL of n-hexane for 20 min at an ultrasonic power of 35 W. The volatile components were analyzed by gas chromatography-mass spectrometry (GC-MS) under the optimal conditions and 57 compounds were identified. The precision, repeatability and stability of the proposed method were also studied. Compared with ultrasonic-assisted extraction(UAE) and hydrodistillation(HD) extraction, the proposed method is more efficient, faster and easier to be operated at room temperature with smaller sample and energy consumption. It is suggested that the ultrasonic nebulization extraction can be used as a novel alternative method for the extraction of volatile components from traditional Chinese patent medicine. 展开更多
关键词 Ultrasonic nebulization extraction gas chromatography-mass spectrometry Volatile component Traditional Chinese patent medicine
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Super Antibiotics, Part II. Hyperforin, Mass Spectroscopy (MS) and Gas Chromatography-Mass Spectrometry (GC-MS), Evidence of Permeability of the Blood-Testis Barrier (BTB) and the Blood-Brain Barrier (BBB) to Hyperforin 被引量:2
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作者 Ilia Brondz 《International Journal of Analytical Mass Spectrometry and Chromatography》 2016年第4期66-73,共8页
In the first article of this series, we presented some evidence of hyperforin as an antibiotic, antiprotozoal, antiviral, anticancer, and immunomodulatory substance. In the present article, evidence of the permeabilit... In the first article of this series, we presented some evidence of hyperforin as an antibiotic, antiprotozoal, antiviral, anticancer, and immunomodulatory substance. In the present article, evidence of the permeability of the blood-testis barrier (BTB) and blood-brain barrier (BBB) to hyperforin and its distribution in other organs of the domestic pig (Sus scrofa domesticus) are revealed. Seven-month-old male boars with a body mass of 100 kg were fed a diet containing hyperforin. Organs were surgically removed under anesthesia. Organs were suitable prepared and extracted, and then analyzed using gas chromatography-mass spectrometry with supersonic molecular beams (GC-MS with SMB). The presence of hyperforin was recorded in all organs and body fluids. Special attention was paid to the evaluation of the presence of hyperforin in the brain and testes of experimental animals. The presence of hyperforin in the brain and testes of experimental animals was established by GC-MS with SMB. The results are of interest because penicillin and numerous other antibiotics cannot pass through the BTB or BBB if healthy or non-inflamed, which limits their use in patients with meningitis and gonorrhea. The findings are also of interest in cases of penicillin- and multi-antibiotic-resistant bacterial infections. 展开更多
关键词 ANTIBIOTICS HYPERFORIN Super antibiotic Mass Spectroscopy gas chromatography-mass Spectrometry Blood-Testis Barrier Blood-Brain Barrier Methicillin-Resistant Staphylococcus aureus (MRSA)
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Determination of Natural Rubber Content in Taraxacum Kok-Saghyz by Pyrolysis Gas Chromatography-Mass Spectrometry 被引量:1
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作者 Wang Lu Guo Tianyang +3 位作者 Zhang Qing Ma Qiang Dong Yiyang Zhang Jichuan 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2020年第3期43-48,共6页
Nowadays,natural rubber(NR)is an indispensable material for industrial production and peoples’daily utilization.The root of Taraxacum kok-saghyz(TKS)contains a large amount of NR,which is potentially to be an alterna... Nowadays,natural rubber(NR)is an indispensable material for industrial production and peoples’daily utilization.The root of Taraxacum kok-saghyz(TKS)contains a large amount of NR,which is potentially to be an alternative rubber source of conventional Hevea brasiliensis(HB).In order to find a convenient,fast and green method for qualitative and quantitative analysis of NR in TKS,a pyrolysis gas chromatography-mass spectrometric(Py-GCMS)method was developed accordingly.The results indicated that the main products of TKS rubber after pyrolysis were isoprene and limonene,respectively,and the limit of detection(LOD)of TKS rubber was 2.603 mg/g.The ratios of NR mass fractions in TKSs by Py-GC-MS ranged from 1.20%±0.20%to 8.61%±0.28%.The developed method has been used for determination of actual TKS samples and can be further applied to the field test for rapid breeding and large-scale cultivation of TKS thereof. 展开更多
关键词 Taraxacum kok-saghyz(TKS) natural rubber(NR) pyrolysis gas chromatography-mass spectrometry(Py-GCMS) quantification
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Determination of Aroma Composition of Santalum album Linn by Solid-phase Microextraction-Gas Chromatography-Mass Spectrometry
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作者 Guotong CHEN Meiqin LI +2 位作者 Chao HUANG Na WEN Aixia WANG 《Asian Agricultural Research》 2020年第9期43-45,共3页
[Objectives]This study aimed to determine the volatile components in Santalum album Linn and gradually clarify the aroma composition of S.album Linn.[Methods]Solid-phase microextraction method was used to obtain the v... [Objectives]This study aimed to determine the volatile components in Santalum album Linn and gradually clarify the aroma composition of S.album Linn.[Methods]Solid-phase microextraction method was used to obtain the volatile components of S.album Linn.The aroma components were analyzed by gas chromatography-mass spectrometry and their relative contents were calculated using the area normalization method.[Results]In a dry state at room temperature,39 chemical components were identified from S.album Linn,mainly olefins(91.15%),alkanes(3.00%),alcohols(2.56%),esters(2.19%),ketones(0.55%),aldehydes(0.41%)and heterocyclics(0.14%).[Conclusions]This method has the advantages of low sample consumption,easy operation,rapid identification of aroma components and high sensitivity,and can effectively separate and determine volatile components in S.album Linn,realizing the rapid identification of different S.album Linn varieties and providing technical support for further research on Chinese medicinal materials. 展开更多
关键词 Santalum album Linn Solid-phase microextraction(SPME) gas chromatography-mass spectrometry Aroma component
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Direct Determination of Polychlorinated-Biphenyls in Automotive Shredder Residues by Gas Chromatography-Mass Spectrometry
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作者 María de los D. E. Otero Mohamed N. K. Sayadi Luis María Polo Díez 《Journal of Analytical Sciences, Methods and Instrumentation》 2013年第2期90-97,共8页
An easy and rapid method is proposed for the determination of PCBs in automotive shredder residues, using gas chromatography combined with low resolution mass spectrometry (GC-MS). It is based on direct n-hexane solid... An easy and rapid method is proposed for the determination of PCBs in automotive shredder residues, using gas chromatography combined with low resolution mass spectrometry (GC-MS). It is based on direct n-hexane solid-liquid extraction, subtracting background of the lineal aliphatic hydrocarbon interferences and integration of chromatographic peaks containing selected ion PCBs masses (256, 292 and 326 m/z), which are common in all PCBs formulations. Recoveries were in the 80% - 120% range;PCBs were detected and quantified in shredder samples from an automotive shredder industry, thus indicating the validity of the method. 展开更多
关键词 PCBS SOLID-LIQUID Extraction AUTOMOTIVE SHREDDER RESIDUES gas chromatography-mass SPECTROMETRY (GC-MS)
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Preparation and Characterization of Phosphorus Pentafluoride Gas for Lithium Ion Battery Electrolyte Salt 被引量:1
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作者 LIU Jian-wen LI Xin-hai WANG Zhi-xing GUO Hua-jun HU Qi-yang 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2009年第6期791-795,共5页
A novel preparation method of phosphorus pentafluoride(PF5) is introduced in details in the article. Phosphorus pentafluoride is mainly used to synthesize lithium ion battery electrolyte salt. In the experiment mesn... A novel preparation method of phosphorus pentafluoride(PF5) is introduced in details in the article. Phosphorus pentafluoride is mainly used to synthesize lithium ion battery electrolyte salt. In the experiment mesneproduct- hexafluorophosphoric acid(HPF6) was firstly prepared-from phosphorus pentoxide(P2O5) and anhydrous hydrogen fluoride(HF), according to the chemical stoichiometrics, the optimum amount of excess HF used was about 60% and the optimum reaction time was 4 h; then HPF6 was dehydrated by oleum with an excess amount of 35%-- 40% which was heated for 40--50 min at 150 ℃; thus HPF6 was decomposed to a mixture of gases containing PF5; impurity gases were removed through condensation in the presence of cooling water at 0 ℃, then PF5 of high purity was eventually prepared. The production was characterized by inffared(IR) spectrometry and gas chromatography-mass spectroscopy-selected ion monitoring(GC-MS-SIM). Eventual results indicate that PF5 prepared by the novel method has a high target purity and a low amount of impurity and water. 展开更多
关键词 Hexafluorophosphoric acid Phosphorus pentafluoride PREPARATION lnfrared spectrum gas chromatogra- phy-mass spectroscopy-selected ion monitoring
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Triacontyl modified silica gel as a sorbent for the preconcentration of polycyclic aromatic hydrocarbons in aqueous samples prior to gas chromatographic-mass spectrometry determination 被引量:1
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作者 Tsuneaki Maeda 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第6期-,共4页
Triacontyl modified silica gel as a sorbent coupled with gas chromatography-mass spectrometry(GC-MS) was developed to determine EPA prior 16 polycyclic aromatic hydrocarbons(PAHs) in water samples.Various parameters o... Triacontyl modified silica gel as a sorbent coupled with gas chromatography-mass spectrometry(GC-MS) was developed to determine EPA prior 16 polycyclic aromatic hydrocarbons(PAHs) in water samples.Various parameters of solid-phase extraction such as organic modifier solvent,eluent,sample flow rate and volume were optimized.The developed method was found to yield a linear calibration curve in the concentration range of 0.05-8μg/L with respect to naphthalene,acenaphthylene,acenaphthene and 0.01-8μg/L for dibenz[a,h]anthracene and 0.05-14μg/L for fluorene,phenanthrene,anthracene and 0.01-14μg/L for the rest of analytes.Furthermore,the good accuracy and repeatability of the method made sure the requirements for achieving reliable analysis of PAHs in the environmental water samples,and the recoveries of optimal method were in the range of 80-120%except to higher volatility PAHs.C_(30)-bonded silica was proved to be an efficient sorbent for extraction of high molecular weight PAHs. 展开更多
关键词 Polycyclic aromatic hydrocarbons C30-bonded silica gas chromatography-mass spectrometry Solid-phase extraction Water analysis
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ACQUIRING AND PATTERN RECOGNITION OF SPECTRUM INFORMATION OF WELDING METAL TRANSFER
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作者 HanGuoming HeYu YunShaohui LiJunyue 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第3期319-322,共4页
In order to recognize various metal transfer modes, by the creation of apattern recognition system for metal transfer mode, five kinds of spectrum signal in gas metal arcwelding (MIG, MAG and CO_2) are collected and t... In order to recognize various metal transfer modes, by the creation of apattern recognition system for metal transfer mode, five kinds of spectrum signal in gas metal arcwelding (MIG, MAG and CO_2) are collected and taken as training samples. These samples arepretreated by computer. Several key characteristic parameters of the spectrum signal are creativelyextracted, and a corresponding recognition function and a minimum-distance-classifier areconstructed. The results show that using this method, the pattern recognition of several kinds ofmetal transfer mode for the metal gas arc welding can be done successfully. It has good accuracy andrecognition precision, basis for controlling the metal gas arc welding metal transferautomatically, and relative important parameters in welding process, such as the frequency ofdroplet transfer and the approximate diameter of each droplet, can also be obtained. 展开更多
关键词 gas metal arc welding Metal transfer spectrum Acquiring PATTERNRECOGNITION
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Superfluid phases and excitations in a cold gas of d-wave interacting bosonic atoms and molecules
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作者 李泽汉 Jian-Song Pan W Vincent Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第6期463-468,共6页
Motivated by recent advances in orbitally tuned Feshbach resonance experiments, we analyze the ground-state phase diagram and related low-energy excitation spectra of a d-wave interacting Bose gas. A two-channel model... Motivated by recent advances in orbitally tuned Feshbach resonance experiments, we analyze the ground-state phase diagram and related low-energy excitation spectra of a d-wave interacting Bose gas. A two-channel model with d-wave symmetric interactions and background s-wave interactions is adopted to characterize the gas. The ground state is found to have three interesting superfluid phases: atomic, molecular, and atomic–molecular. In great contrast to what was previously known about the p-wave case, the atomic superfluid is found to be momentum-independent for the d-wave case discussed here. The Bogoliubov spectra above each superfluid phase are obtained both analytically and numerically. 展开更多
关键词 d-wave interaction quantum gas Bogoliubov spectrum SUPERFLUID
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Super Antibiotics, Part IV. Hyperforin, Relative and Absolute Stereochemistry Elucidated by Gas-Chromatography Mass-Spectrometry with Supersonic Molecular Beams
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作者 Ilia Brondz 《International Journal of Analytical Mass Spectrometry and Chromatography》 2017年第3期70-85,共16页
Relative and absolute stereochemistry for hyperforin has been proposed by Brondz et al. was supported and new isomer of hyperforin-perforatrin has been discovered. Relative and absolute stereochemistry for perforatrin... Relative and absolute stereochemistry for hyperforin has been proposed by Brondz et al. was supported and new isomer of hyperforin-perforatrin has been discovered. Relative and absolute stereochemistry for perforatrin was proposed and elucidated by using gas-chromatography mass-spectrometry with supersonic molecular beams (SMB). The possibility of the existence of ambiguities in chirality as a hypothesis for the existence, and a new understanding, of chiral substances with shifting chirality is presented. 展开更多
关键词 HYPERFORIN Perforatrin RELATIVE and Absolute STEREOCHEMISTRY gas chromatography-mass SPECTROMETRY CHIRALITY
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Intra-Cavity Absorption Sensors for Gas Detection Using Wavelength Sweep Technique
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作者 Kun Liu Wen-Cai Jing +6 位作者 Gang-Ding Peng Jian-Zhong Zhang Yan Wang Tie-Gen Liu Da-Gong Jia Hong-Xia Zhang Yi-Mo Zhang 《Journal of Electronic Science and Technology of China》 2008年第4期369-372,共4页
Wavelength sweep technique (WST) is introduced into intra-cavity fiber laser (ICFL) for low concentration gas detection. The limitation induced by noise can be eliminated using this method, and the performance of ... Wavelength sweep technique (WST) is introduced into intra-cavity fiber laser (ICFL) for low concentration gas detection. The limitation induced by noise can be eliminated using this method, and the performance of the system is improved. The sensitivity of the system is reduced to less than 300 ppm. With WST, sweeping characteristic of the ICFL can be described according to known gas absorption spectra. 展开更多
关键词 gas detection optical fiber laser spectrum analysis wavelength measurement.
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