期刊文献+
共找到83,858篇文章
< 1 2 250 >
每页显示 20 50 100
Gas Chromatographic Method for Identification and Quantification of Commonly Used Residual Solvents in Pharmaceuticals Products
1
作者 Sreekanta Nath Dalal Pranab Kumar Das 《American Journal of Analytical Chemistry》 CAS 2024年第8期241-252,共12页
Background: Impurities are not expected in the final pharmaceutical products. All impurities should be regulated in both drug substances and drug products in accordance with pharmacopeias and ICH guidelines. Three dif... Background: Impurities are not expected in the final pharmaceutical products. All impurities should be regulated in both drug substances and drug products in accordance with pharmacopeias and ICH guidelines. Three different types of impurities are generally available in the pharmaceutical’s product specification: organic impurities, inorganic impurities, and residual solvents. Residual solvents are organic volatile chemicals used or generated during the manufacturing of drug substances or drug products. Purpose: The aim of this study is to develop a cost-effective gas chromatographic method for the identification and quantification of some commonly used solvents—methanol, acetone, isopropyl alcohol (IPA), methylene chloride, ethyl acetate, tetrahydrofuran (THF), benzene, toluene, and pyridine—in pharmaceutical product manufacturing. This method will be able to identify and quantify the multiple solvents within a single gas chromatographic procedure. Method: A gas chromatography (GC) equipped with a headspace sampler and a flame ionization detector, and a column DB 624, 30-meter-long × 0.32-millimeter internal diameter, 1,8 μm-thick, Brand-Agilent was used to develop this method. The initial GC oven temperature was 40°C and held for 5 minutes. It was then increase to 80˚C at a rate of 2˚C per minute, followed by a further increase to 225˚C at a rate of 30˚C per minute, with a final hold at 225˚C for 10 minutes. Nitrogen was used as a carrier gas at a flow rate of 1.20 mL per minute. Dimethyl sulfoxide (DMSO) was selected as sample solvent. Results: The developed method is precise and specific. The percent RSD for the areas of six replicate injections of this gas chromatographic method was within 10.0 and the recovery result found within 80.0% to 120.0%. 展开更多
关键词 Method Development Gas chromatography Compendial Method GDP SPECIFICITY RECOVERY
下载PDF
Simultaneous purification of minor components in natural products using twin-column recycling chromatography with a step solvent gradient
2
作者 Guangxia Jin Yuxue Wu Feng Wei 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第5期212-219,共8页
The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar co... The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar compounds.This study introduces an optimized twin-column recycling chromatography method for the efficient and simultaneous purification of these elusive constituents.By introducing water at a small flowing rate between the twin columns,a step solvent gradient is created,by which the leading edge of concentration band would migrate at a slower rate than the trailing edge as it flowing from the upstream to downstream column.Hence,the band broadening is counterbalanced,resulting in an enrichment effect for those minor components in separation process.Herein,two target substances,which showed similar peak position in high performance liquid chromatography(HPLC)and did not exceed 1.8%in crude paclitaxel were selected as target compounds for separation.By using the twin-column recycling chromatography with a step solvent gradient,a successful purification was achieved in getting the two with the purity almost 100%.We suggest this method is suitable for the separation of most components in natural produces,which shows higher precision and recovery rate compared with the common lab-operated separation ways for natural products(thin-layer chromatography and prep-HPLC). 展开更多
关键词 Solvent gradient Twin-column recycling chromatography PURIFICATION Minor component Natural products
下载PDF
Determination of 14 Organophosphorus Pesticide Residues in Mutton by Gel Permeation Chromatography-Gas Chromatography-Mass Spectrometry(GPC-GC-MS)
3
作者 Junpeng ZHAO Richard Avoi +2 位作者 Azman Bin Atil@Azmi Jiao CHEN Ling YUN 《Agricultural Biotechnology》 2024年第3期28-30,33,共4页
[Objectives]This study was conducted to purify mutton samples by gel permeation chromatography(GPC).[Methods]Fourteen organophosphorus pesticide residues in samples were qualitatively and quantitatively analyzed by ga... [Objectives]This study was conducted to purify mutton samples by gel permeation chromatography(GPC).[Methods]Fourteen organophosphorus pesticide residues in samples were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry(GC-MS)in selective ion scanning mode(SIM).[Results]The organophosphorus pesticide standard solutions showed good linearity in the mass concentration range of 0.1-10.0μg/ml with correlation coefficients(r)not lower than 0.999,and the detection limits(S=3 N)ranged from 0.01 to 0.05 mg/kg.The average recovery values were in the range of 80.2%-99.7%,with relative standard deviations(RSDs,n=3)in the range of 1.8%-6.3%,at the addition levels of 0.5,1.0 and 2.0 mg/kg.[Conclusions]The method is simple,sensitive and accurate,and can be used for the determination of organophosphorus pesticide residues in mutton. 展开更多
关键词 MUTTON Gas chromatography-mass spectrometry Gel permeation chromatography ORGANOPHOSPHORUS Pesticide residue
下载PDF
Comprehensive analysis of phenolic composition and antioxidant mechanisms in Gymnema sylvestre extracts using LC-MS and column chromatography
4
作者 Shengjie Hao Yuxin Du +2 位作者 Jianglong He Qian Li Guilin Chen 《Asian Journal of Traditional Medicines》 2024年第4期211-222,共12页
Recent studies have highlighted the potential of plant extracts as therapeutic agents for managing oxidative stress and related disorders.This study aims to elucidate the phenolic composition and antioxidant propertie... Recent studies have highlighted the potential of plant extracts as therapeutic agents for managing oxidative stress and related disorders.This study aims to elucidate the phenolic composition and antioxidant properties of Gymnema sylvestre extracts.Ethanolic reflux extraction followed by column chromatography was employed to isolate phenolic compounds.The total phenolic and flavonoid contents were quantified using the Folin–Ciocalteu and aluminum chloride colorimetric methods,respectively.Antioxidant activities were assessed by DPPH,ABTS scavenging assays and the ferric reducing antioxidant power(FRAP)assay.High-Performance Liquid Chromatography(HPLC)with a C18 column and Thermo TSQ Quantum Access Max(LC-MS)were used to determine the levels of gymnemic acid and identify other potential phenolic compounds.The analysis revealed significant antioxidant activities in the fractions.Fraction A showed the highest DPPH and ABTS scavenging activities,and Fraction C demonstrated the highest ferric reducing power.LC-MS analysis identified several phenolic compounds,indicating that these are major contributors to the antioxidant efficacy of the extract.This study provides a detailed phenolic profile and confirms the strong antioxidant potential of Gymnema sylvestre leaf extract,supporting its therapeutic use and further investigation. 展开更多
关键词 Gymnema sylvestre ANTIOXIDANTS column chromatography phenolic compounds LC-MS
下载PDF
Determination of Benzo[a]pyrene in Edible Oil by High Performance Liquid Chromatography-Fluorescence Detector (HPLC-FL)
5
作者 Guixia YANG Jie LIU +3 位作者 Xiujuan WANG Fenglan ZHANG Kun XIN Chunli KONG 《Agricultural Biotechnology》 2024年第2期8-9,19,共3页
In this study, an optimized high performance liquid chromatography-fluorescence detector (HPLC-FL) method for the determination of benzo[a]pyrene in edible oil was established. HPLC was performed with Thermo Fisher Sc... In this study, an optimized high performance liquid chromatography-fluorescence detector (HPLC-FL) method for the determination of benzo[a]pyrene in edible oil was established. HPLC was performed with Thermo Fisher Scientific C18 column (250 mm×4.6 mm, 5 μm) as the chromatographic column and acetonitrile and water as the mobile phase, and the excitation wavelength and emission wavelength of fluorescence detector were 286 and 430 nm, respectively. The response was high, and the linear range was 0.5-10.0 ng/ml. The lowest limit of detection was 0.11 ng/ml, and the average recovery was 92.5%. This method is suitable for quantitative analysis of benzo[a]pyrene content in edible oil. 展开更多
关键词 BENZO[A]PYRENE High performance liquid chromatography Fluorescence detector
下载PDF
Determination of Organic Acids in Root Exudates by High Performance Liquid Chromatography: I. Development and Assessment of Chromatographic Conditions *1 被引量:4
6
作者 SHENJIANBO ZHANGFUSUO 《Pedosphere》 SCIE CAS CSCD 1998年第2期97-104,共8页
Methods for determining nine low molecular weight organic acids in root exudates were developed by using reversed phase high performance liquid chromatography with UV (ultraviolet) detection at 214 nm. The mobile ph... Methods for determining nine low molecular weight organic acids in root exudates were developed by using reversed phase high performance liquid chromatography with UV (ultraviolet) detection at 214 nm. The mobile phase was 18 mmol L -1 kH 2PO 4 adjusted to pH 2.25 with phosphoric acid and the flow rate was 0.3 mL min -1 . The analytical column was a reversed phase silica based C 18 column (Shim pack CLC ODS). The root exudates were collected through submerging the whole root system into aerated deionized water for 2 hours. The filtered exudate solutions were concentrated to dryness by rotary evaporation at 40 °C, dissolved in 10 mL mobile phase. The chromatographic conditions of organic acid determination were analyzed. The results showed that there was a high selectivity and sensitivity in the organic acid determination by reversed phase high performance liquid chromatography. Coefficients of variation for organic acid determination were lower than 10% except lactic acid. The recoveries were consistently between 80.1% to 108.3%. Detection limits were approximately 0.05 to 4.5 mg L -1 for organic acids except succinic acid with the detection limit of 7.0 mg L -1 . Phosphorus deficiency may contribute to the release of organic acids in soybean root exudates especially malic, lactic and citric acids. 展开更多
关键词 high performance liquid chromatography organic acids root exudates SOYBEAN
下载PDF
Efficient and selective extraction of uranium from seawater based on a novel pulsed liquid chromatography radionuclide separation method 被引量:2
7
作者 Jian‑Hua Ye Tao Yu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第2期13-27,共15页
The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation met... The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation method was proposed,and a pulsed nuclide automated separation device was developed,alongside a new chromatographic column.The length of this chromatographic column was 10 m,with an internal warp of 3 mm and a packing size of 1 mm,while the total separation units of the column reached 12,250.The most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device:Sample pH in the column=2,sample injection flow rate=5.698 mL/min,chromatographic column heating temperature=60℃.Separation experiments were also carried out for uranium,europium,and sodium ions in mixed solutions;uranium and sodium ions in water samples from the Ganjiang River;and uranium,sodium,and magnesium ions from seawater samples.The separation factors between the different nuclei were then calculated based on the experimental data,and a formula for the separation level was derived.The experimental results showed that the separation factor in the mixed solution of uranium and europium(1:1)was 1.088,while achieving the initial separation of uranium and europium theoretically required a 47-stage separation.Considering the separation factor of 1.50for the uranium and sodium ions in water samples from the Ganjiang River,achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage separation.Furthermore,for the seawater sample separation experiments,the separation factor of uranium and sodium ions was 1.2885;therefore,more than 28 stages of sample separation would be required to achieve uranium extraction from seawater.The novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment,while expanding the possibilities of extracting uranium from seawater through chromatography. 展开更多
关键词 Pulsed liquid chromatography Nuclide separation Seawater uranium extraction Uranium enrichment
下载PDF
MODELLING OF MECHANICAL MECHANISM OF CHROMATOGRAPHIC SYSTEM AND THEORETICAL EQUATIONS SHOWING DYNAMICAL CHARACTERISTICS OF CHROMATOGRAPHY
8
作者 Wei Qun DENG, Jin Fa YANG Fujian Geological Analysis and Testing Research Center,Fuzhou,350002 Yun DENG Department of Chemical Engineering, University of Waterloo, Canada N2L 3GI 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第7期547-550,共4页
A simple model of chromatographic mechanical mechanism is present, and then a scrics of theoretical chromatographic equations and fundamental Formulae are derived. These theoretical equations and formulae not only res... A simple model of chromatographic mechanical mechanism is present, and then a scrics of theoretical chromatographic equations and fundamental Formulae are derived. These theoretical equations and formulae not only reserve thermodynamic characteristics in the current fundamental chromatographic formulae, but also introduce one or more kinetic parameter, so it is possible to make the macroscopic-control on the effect of kinetic characteristics on chromatographic system. 展开更多
关键词 MODELLING OF MECHANICAL MECHANISM OF CHROMATOGRAPHIC SYSTEM AND THEORETICAL EQUATIONS SHOWING DYNAMICAL CHARACTERISTICS OF chromatography 月山
下载PDF
Separation and analysis of six fractions in low temperature coal tar by column chromatography
9
作者 Shuangtai Liu Lei He +5 位作者 Qiuxiang Yao Xi Li Linyang Wang Jing Wang Ming Sun Xiaoxun Ma 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第6期256-265,共10页
The low temperature coal tar(CT)is taken as the raw material,and the extraction and column chromatography are used for detailed and accurate characterization in this paper.The n-heptane soluble fraction(CT-HS)and inso... The low temperature coal tar(CT)is taken as the raw material,and the extraction and column chromatography are used for detailed and accurate characterization in this paper.The n-heptane soluble fraction(CT-HS)and insoluble fraction(CT-HI)were obtained by n-heptane Soxhlet extraction.The extraction rate of CT-HS reached 92.79%(mass),which indicated that there are few heavy compounds in it.Further,different solvents(methylbenzene,benzene,ethyl acetate,methylbenzene-ethanol)were used to elute CT-HS by chromatographic column to obtain five fractions(saturates,aromatics,heteroatoms,phenolics and resins,named CT-SA,CT-AR,CT-HE,CT-PH,CT-RE,respectively).The yields of CTSA,CT-AR,CT-HE,CT-PH,CT-RE are 42.12%,10.43%,2.19%,9.50%and 6.63%(mass),respectively.Gas chromatography-mass spectrometry analysis of eluting components show that alkanes are the main components in CT,followed by polycyclic aromatics,and the corresponding fractions are CT-SA and CT-AR,respectively.The relative content of aliphatics in CT-SA is 76.93%,and the relative content of aromatics in CT-AR is 75.05%.This separation technology effectively separates and enriches different components in CT,and the activation energy required for the pyrolysis process of a single eluting fraction is lower than that of CT,which is expected to provide an important reference for the separation,analysis and conversion of complex oil products such as coal-oil co-processing products,coal tar and other complex heavy carbon oil products. 展开更多
关键词 Low temperature coal tar Extractive separation Column chromatography isolation chromatography/mass spectrometry
下载PDF
A High-Performance Liquid Chromatography Method for the Simultaneous Determination of Five Index Components in Danhong Injection
10
作者 Yun An Tian Tian +2 位作者 Qinglin Wang Xingchu Gong Chenchen Wang 《American Journal of Analytical Chemistry》 CAS 2023年第11期481-492,共12页
The purpose of this study was to establish a high-performance liquid chromatography (HPLC) method for the simultaneous determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, a... The purpose of this study was to establish a high-performance liquid chromatography (HPLC) method for the simultaneous determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, and 4-coumaric acid in Danhong injection. The chromatographic method employed was as follows: the column was a Welch Ultimate XB-C18 column (250 mm × 4.6 mm, 10 μm), the mobile phase was a gradient elution of 0.4% formic acid aqueous solution (A) and acetonitrile (B), the detection wavelengths were 280 nm for sodium danshensu, protocatechuic aldehyde, and salvianolic acid B and 326 nm for 4-coumaric acid and rosmarinic acid, the sample volume was 10 μL, the flow rate was 1.0 mL/min, and the column temperature was 35°C. This method can realize the separation and determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, and 4-coumaric acid within 50 minutes. The linear relationships of the five peak areas and their concentrations are good (R2> 0.9997). The precision RSD values are all less than 1.0%. The reproducibility RSD values are all less than 1.3%. The stability RSD values are all less than 2.2%. The recovery values ranged from 92.4% to 99.4%. This method is simple, accurate, and reproducible. It can be used for the determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, and 4-coumaric acid in Danhong injection. 展开更多
关键词 Danhong Injection High Performance Liquid chromatography Phenolic Acid FLAVONOIDS
下载PDF
Determination of Voriconazole in Human Plasma by Liquid Chromatography Tandem Mass Spectrometry: Application in Therapeutic Drug Monitoring
11
作者 Waleed Alhussaini Ezzeldeen Ghanem +4 位作者 Magd Alsahly Amani Kurdi Eman Alharbi Imadul Islam Majed Aljeraisy 《American Journal of Analytical Chemistry》 2023年第9期378-389,共12页
A sensitive, accurate and robust Liquid Chromatography Tandem Mass Spectrometry method has been developed and validated to measure voriconazole trough levels in human plasma. The plasma samples were mixed with flucona... A sensitive, accurate and robust Liquid Chromatography Tandem Mass Spectrometry method has been developed and validated to measure voriconazole trough levels in human plasma. The plasma samples were mixed with fluconazole as an Internal Standard and directed to protein precipitation and drug extraction. An aliquot of 1 μl was injected into the chromatographic system and separated by the Acquity BEH C18 column at a flow rate of 0.30 ml/min in a gradient mobile phase consisting of acetonitrile, Ultrapure water (UPW), methanol and formic acid. Voriconazole was detected by a Triple Quadrupole Detector (TQD) operating on Multiple Reaction Monitoring (MRM) and a positive ion mode Electrospray ionization (ESI) Q1 mass: 350.1 m/z, Q3 mass: 281.1 m/z. Method linearity of the calibration curve (0.10 - 8.00 μg/ml) indicated a correlation coefficient r ≥ 0.99. The intra and inter-assay accuracy was within 85% - 115% and the intra and inter-assay precision was ≤5.76%. Voriconazole recovery percentage was between 97.69 - 119.62%. The method was successively applied in routine voriconazole TDM. 展开更多
关键词 VORICONAZOLE Human Plasma Liquid chromatography Tandem Mass Spectrometry Therapeutic Drug Monitoring
下载PDF
Phytochemical Screening and Chromatographic Purification of Bauhunia semibifida ROXB Hexane-Dichloromethane Leaf Extract
12
作者 Ikenna Obiora Alaekwe Vincent Ishmel Egbulefu Ajiwe Chinedu Chris Aguoma 《Journal of Materials Science and Chemical Engineering》 2023年第7期14-19,共6页
Bauhunia semibifida is among the several plants that have been studied for their medicinal properties. Bauhunia is native to India. However, some species have been found in Africa. It has several important uses, such ... Bauhunia semibifida is among the several plants that have been studied for their medicinal properties. Bauhunia is native to India. However, some species have been found in Africa. It has several important uses, such as anti-bacterial, anti-inflammatory and anti-cancerous. This study is aimed primarily at carrying out a preliminary phytochemical screening to ascertain the classes of bioactive compounds present in Bauhunia semibifida and ascertain the solvent system(s) for their separation. Several solvents were used for the extraction as well as in the chromatographic profiling of all the products of extraction. Thin layer chromatography was performed on silica gel-coated glass plates using several mobile phase protocols (Hexane: Ethylacetate, Dichloromethane (DCM): Methanol). Further purification of the extracts was done using classical column (CcSiO<sub>2</sub>) and gel filtration chromatography. TLC profiling of DCM and Hexane extracts shows the same Rf values of less than 1 and are thus combined to give the Hexane/DCM extract, which gave two compounds following isocratic elution from column chromatography. Phytochemical screening of the extract showed the presence of Tannins, Cardiac glycosides, Alkaloids, Flavonoids and Phenolic compounds. Hexane/DCM extract thus contains phytocompounds which can further be studied. 展开更多
关键词 Bauhinia semibifida Phytochemical Screening HERBS Medicinal Plants chromatography
下载PDF
Preparation Process and Thin Layer Chromatography Identification of Wufang Babu Poultice
13
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
Ash Detection of Coal Slime Flotation Tailings Based on Chromatographic Filter Paper Sampling and Multi-Scale Residual Network
14
作者 Wenbo Zhu Neng Liu +4 位作者 Zhengjun Zhu Haibing Li Weijie Fu Zhongbo Zhang Xinghao Zhang 《Intelligent Automation & Soft Computing》 2023年第12期259-273,共15页
The detection of ash content in coal slime flotation tailings using deep learning can be hindered by various factors such as foam,impurities,and changing lighting conditions that disrupt the collection of tailings ima... The detection of ash content in coal slime flotation tailings using deep learning can be hindered by various factors such as foam,impurities,and changing lighting conditions that disrupt the collection of tailings images.To address this challenge,we present a method for ash content detection in coal slime flotation tailings.This method utilizes chromatographic filter paper sampling and a multi-scale residual network,which we refer to as MRCN.Initially,tailings are sampled using chromatographic filter paper to obtain static tailings images,effectively isolating interference factors at the flotation site.Subsequently,the MRCN,consisting of a multi-scale residual network,is employed to extract image features and compute ash content.Within the MRCN structure,tailings images undergo convolution operations through two parallel branches that utilize convolution kernels of different sizes,enabling the extraction of image features at various scales and capturing a more comprehensive representation of the ash content information.Furthermore,a channel attention mechanism is integrated to enhance the performance of the model.The combination of the multi-scale residual structure and the channel attention mechanism within MRCN results in robust capabilities for image feature extraction and ash content detection.Comparative experiments demonstrate that this proposed approach,based on chromatographic filter paper sampling and the multi-scale residual network,exhibits significantly superior performance in the detection of ash content in coal slime flotation tailings. 展开更多
关键词 Coal slime flotation ash detection chromatography filter paper multi-scale residual network
下载PDF
采用气相色谱-质谱指纹图谱鉴定铁木豆属木材 被引量:1
15
作者 吴静霞 顾钰华 +3 位作者 姚晨岚 肖湾 龚青 李倩 《化学分析计量》 CAS 2024年第2期82-86,92,共6页
采用气相色谱-质谱指纹图谱分别鉴定平萼铁木豆、葱叶状铁木豆和马达加斯加铁木豆属木材。以二氯甲烷提取样品中的特定化合物,采用气相色谱-质谱法分析提取物,建立目标物色谱图。平萼铁木豆在保留时间25.1 min的最强吸收峰和22.3、22.6... 采用气相色谱-质谱指纹图谱分别鉴定平萼铁木豆、葱叶状铁木豆和马达加斯加铁木豆属木材。以二氯甲烷提取样品中的特定化合物,采用气相色谱-质谱法分析提取物,建立目标物色谱图。平萼铁木豆在保留时间25.1 min的最强吸收峰和22.3、22.6及23.4 min的次强吸收峰可作为平萼铁木豆的特征图谱,与其他两种铁木豆相区分。葱叶状铁木豆和马达加斯加铁木豆的最强吸收峰色谱保留时间均为16.3 min,葱叶状铁木豆的次强吸收峰色谱保留时间为18.5 min,另外还在色谱保留时间分别为19.4、19.8、24.3 min处有吸收峰,而马达加斯加铁木豆除在色谱保留时间17.7 min处有次强吸收峰外,还在色谱保留时间为23.4 min时有吸收峰。气相色谱-质谱法可用于平萼铁木豆、葱叶状铁木豆和马达加斯加铁木豆三类木材的鉴别。 展开更多
关键词 木材 气相色谱-质谱联用仪 铁木豆
下载PDF
免疫亲和层析技术协同酶联免疫吸附法检测赭曲霉毒素A 被引量:1
16
作者 张蕴哲 张先舟 +1 位作者 袁耀武 张伟 《食品科学》 EI CAS CSCD 北大核心 2024年第10期257-264,共8页
利用免疫亲和层析技术(immunoaffinity chromatography,IAC)对样品中赭曲霉毒素A(ochratoxin A,OTA)进行捕获与浓缩,利用酶联免疫吸附(enzyme-linked immunosorbent assay,ELISA)法对IAC捕获的目标物OTA进行测定。IAC与ELISA中的抗OTA... 利用免疫亲和层析技术(immunoaffinity chromatography,IAC)对样品中赭曲霉毒素A(ochratoxin A,OTA)进行捕获与浓缩,利用酶联免疫吸附(enzyme-linked immunosorbent assay,ELISA)法对IAC捕获的目标物OTA进行测定。IAC与ELISA中的抗OTA单克隆抗体来自不同的克隆株,分属不同独特型,与OTA结合靶点的选择性存在差异,IAC与ELISA协同检测,可以有效过滤OTA结构类似物造成的干扰,提高免疫分析的特异性与灵敏度。该方法用于加标样品测定时,OTA的检出限为0.2 ng/g,定量限为0.4 ng/g,OTA的平均回收率为75.9%,与单一的ELISA法相比,该方法虽然回收率略低,但灵敏度可以显著提高,达到ELISA法的60倍。通过对49份样品的实际检测,该方法检出阳性样品与国标法的符合率达到100%,漏检率为0%,由此可见,该方法在准确性上表现出明显的优势。作为一种综合免疫分析技术,该方法不需要大型仪器设备,对操作环境没有严格要求,便于基层实验室对样品中OTA的分析。 展开更多
关键词 免疫亲和层析技术 酶联免疫吸附法 检测 赭曲霉毒素A
下载PDF
基于GC-IMS和GC-MS技术结合化学计量法分析干燥方式对香椿挥发性成分的影响 被引量:1
17
作者 张乐 魏依馨 +5 位作者 史冠莹 蒋鹏飞 赵丽丽 王继红 张少南 王赵改 《食品工业科技》 CAS 北大核心 2024年第11期222-234,共13页
为研究干燥方式对香椿挥发性风味物质的影响,利用气相色谱-离子迁移谱技术(gaschromatography-ion mobility spectrometry,GC-IMS)和气相色谱-质谱联用技术(gas chromatography-mass spectrometry,GC-MS)、相对香气活性值(relative odor... 为研究干燥方式对香椿挥发性风味物质的影响,利用气相色谱-离子迁移谱技术(gaschromatography-ion mobility spectrometry,GC-IMS)和气相色谱-质谱联用技术(gas chromatography-mass spectrometry,GC-MS)、相对香气活性值(relative odor activity value,ROAV)对真空冷冻干燥、热泵干燥、热风干燥、微波真空干燥的香椿样品进行挥发性成分分析,并进一步结合化学计量方法主成分分析(principal component analysis,PCA)和偏最小二乘判别分析(partial least squares-discriminant analysis,PLS-DA),探究样品间挥发性成分的差异性。结果表明,通过GC-IMS检测到78个峰,鉴定出59种化合物。通过GC-MS鉴定出94种挥发性化合物,主要挥发性成分是硫化物、烯烃类和醛类。经过干燥后总挥发性化合物的含量显著降低。通过ROAV法确定了(E,Z)-二-1-丙烯基二硫化物、2-巯基-3,4-二甲基-2,3-二氢噻吩、正己醛、2-己烯醛、丁香酚等为香椿样品中关键香气化合物。PCA和PLS-DA结果表明,不同干燥方式的样品与新鲜样品有明显的分离,彼此之间也有明显的区别。鲜样和真空冷冻干燥样品为一组,其他3个干燥香椿样品为一组。根据变量投影重要性(variable importance in projection,VIP)得分共筛选出10种(VIP>1)标志挥发性化合物。干燥方式对香椿风味特性影响显著,真空冷冻干燥组与鲜样最为接近,考虑实际应用热泵干燥为香椿最适宜的脱水方式。本研究为热加工过程中风味品质控制提供一定的理论参考。 展开更多
关键词 香椿 干燥方式 气相色谱-离子迁移谱(GC-IMS) 气相色谱-质谱联用技术(GC-MS) 挥发性化合物
下载PDF
气相色谱-三重四极杆质谱法测定黄芪中42种农药残留 被引量:2
18
作者 田丽 胡佳薇 +1 位作者 尹丹阳 王敏娟 《食品安全质量检测学报》 CAS 2024年第7期225-233,共9页
目的建立气相色谱-三重四极杆质谱法测定黄芪中42种农药的方法。方法黄芪中的多组分农药采用乙腈提取,上清液经N-丙基乙二胺、十八烷基硅烷键合硅胶、硅胶净化,采用程序升温进样口上机测定,基质匹配曲线外标法定量。结果42种农药在0.01~... 目的建立气相色谱-三重四极杆质谱法测定黄芪中42种农药的方法。方法黄芪中的多组分农药采用乙腈提取,上清液经N-丙基乙二胺、十八烷基硅烷键合硅胶、硅胶净化,采用程序升温进样口上机测定,基质匹配曲线外标法定量。结果42种农药在0.01~1.00μg/mL范围内线性关系良好,相关系数为0.9954~0.9999,在空白基质中添加低(0.02 mg/kg)、中(0.40 mg/kg)、高(2.00 mg/kg)3个不同浓度的混合标准品各6份,加标回收率为72.5%~109.3%,相对标准偏差为1.25%~6.07%,检出限为0.002~0.010mg/kg,定量限为0.005~0.030 mg/kg。在100批次黄芪样本中检出6种农药,分别是α-硫丹、对硫磷、甲基对硫磷、硫环磷、氯氰菊酯、氰戊菊酯,样品检出率6.0%,样品超标率1.0%,超标农药为氯氰菊酯。结论本方法灵敏度高、准确性好,适用于黄芪中42种农药的同时测定。 展开更多
关键词 气相色谱-三重四极杆质谱法 农药残留 黄芪
下载PDF
基于HS-GC-IMS和HS-SPME-GC-MS的蛋白酶对豆粕挥发性风味的影响分析 被引量:1
19
作者 齐宝坤 刘雨雯 +3 位作者 姚玉雪 吴思雨 孙树坤 陈昊 《农业机械学报》 EI CAS CSCD 北大核心 2024年第4期352-367,410,共17页
为研究不同蛋白酶酶解对豆粕挥发性风味成分的影响,选用4种蛋白酶(碱性蛋白酶、中性蛋白酶、木瓜蛋白酶、风味蛋白酶)对豆粕进行酶解,采用顶空-气相色谱-离子迁移谱(Headspace-gas chromatography-ion mobility spectroscopy,HS-GC-IMS... 为研究不同蛋白酶酶解对豆粕挥发性风味成分的影响,选用4种蛋白酶(碱性蛋白酶、中性蛋白酶、木瓜蛋白酶、风味蛋白酶)对豆粕进行酶解,采用顶空-气相色谱-离子迁移谱(Headspace-gas chromatography-ion mobility spectroscopy,HS-GC-IMS)和顶空固相微萃取-气相色谱-质谱(Headspace solid phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS)联用技术分析不同豆粕酶解物(Soybean meal hydrolysates,SMH)的挥发性风味成分,并结合主成分分析(Principal component analysis,PCA)、热图聚类和正交偏最小二乘判别法(Orthogonal partial least squares-discriminant analysis,OPLS-DA)对不同SMH进行分析。结果表明:碱性蛋白酶、中性蛋白酶、木瓜蛋白酶和风味蛋白酶酶解豆粕的挥发性风味成分存在较大差异。HS-GC-IMS鉴定出84种挥发性成分,筛选得到33种差异风味物质,发现酶解后酮类物质显著降低而醛类、醇类和酯类物质含量明显增加。PCA结果表明不同SMH之间的风味存在显著差异。最终通过OPLS-DA筛选出贡献较大的挥发性化合物,同时构建出可靠的用以鉴别SMH的模型。HS-SPME-GC-MS检测出103种差异风味物质,可用于区分不同SMH,被检出的挥发性组分中醛类、醇类和酮类等化合物为SMH风味的形成做出主要贡献,明晰了部分风味化合物形成的原因。PCA和聚类热图结果表明不同蛋白酶酶解对豆粕的挥发性风味物质的种类和含量有显著影响,其中,风味蛋白酶和木瓜蛋白酶对豆粕的风味改善最为显著。 展开更多
关键词 豆粕 酶解 顶空-气相色谱-离子迁移谱 顶空固相微萃取-气相色谱-质谱
下载PDF
HPLC及LC-MS测定榛子中氯吡苯脲和多菌灵残留 被引量:1
20
作者 桑育黎 王沛 +2 位作者 郝延军 李楠楠 戚建忠 《辽宁大学学报(自然科学版)》 CAS 2024年第1期8-15,共8页
本文采用高效液相色谱法(HPLC)和液相色谱-质谱法(LC-MS)对干果榛子中氯吡苯脲和多菌灵残留量进行含量测定.HPLC和LC-MS均使用C18色谱柱,含量测定采取等度洗脱,流动相:甲醇-水(55∶45,体积比);体积流量:1.0 mL·min-1;测定波长:260 ... 本文采用高效液相色谱法(HPLC)和液相色谱-质谱法(LC-MS)对干果榛子中氯吡苯脲和多菌灵残留量进行含量测定.HPLC和LC-MS均使用C18色谱柱,含量测定采取等度洗脱,流动相:甲醇-水(55∶45,体积比);体积流量:1.0 mL·min-1;测定波长:260 nm;柱温:30℃.LC-MS采取电喷雾离子源,梯度洗脱,体积流量:0.6 mL·min-1,柱温:30℃.结果表明,榛子中氯吡苯脲与多菌灵存在残留,氯吡苯脲质量浓度在1.00~10.00μg·mL-1范围内线性关系良好,加样回收率在95.58%~100.58%;多菌灵质量浓度在1.005~15.075μg·mL-1范围内具有良好的线性关系,加样回收率在95.61%~104.39%.实验证明,HPLC与LC-MS相结合的方法具有操作简便、灵敏度高、检出限低等优点,能有效地检测到榛子样品中膨大剂氯吡苯脲及杀菌剂多菌灵的残留,并确定其残留量,线性关系和回收率结果均令人满意.根据被检测的8批样品中氯吡苯脲和多菌灵两项农药残留量推断,作为一般干果食用榛子是安全的. 展开更多
关键词 榛子 氯吡苯脲 多菌灵 高效液相色谱法(HPLC) 液相色谱-质谱法(LC-MS)
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部