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Effect of Methanol in the Wash-Solvent Bottle and the OnGuard Cartridges on the Determination of Different Anions Using Ion chromatography

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American Journal of Analytical Chemistry 2012年第2期3卷 175-179页

作者： Adnan Manassra Mustafa Khamis Fida Obeidi Majdi Dakiky Fuad Al-Rimawi Faculty of Science and Technology Al-Quds University East Jerusalem Palestine

The effect of using methanol in the flush-solvent bottle of the auto-sampler of Ion Chromatograph on the determination of sulfate ions was studied using AS11-HC 2 mm analytical column. The use of 50% methanol in the flush solvent bottle results in overestimation of sulfate concentration by 18%. However, the use of 10% methanol instead of 50% did not show such error in the determination of sulfate using the same column. Furthermore, the effect of using OnGuard-RP and OnGuard-P cartridges for sample pretreatment on the determination of different anions was also studies using AS14-HC 2 mm analytical column. The results indicate that using OnGuard-RP cartridge caused the concentration of fluoride, bromide, nitrate, phosphate and sulfate ions to be underestimated, whereas the concentration of chloride ions to be overestimated. The error in the determination of fluoride, bromide, nitrate, phosphate sulfate, and chloride was found to be 40.0%, 26.0%, 22.8%, 26.8%, 18.0%, and 25.0% of the certified standard concentration, respectively. It was also found that the use of OnGuard-P cartridge resulted in underestimation of fluoride, chloride, bromide, nitrate, phosphate, and sulfate by 60.0%, 40.0%, 82.0%, 87.2%, 45.2%, and 39.0% of the certified standard concentration, respectively. These findings point out to careful corrections that should be considered in any application of ion chromatography utilizing such sample pretreatment.

关键词： Ion chromatography Interference Anions Methanol OnGuard Cartridges

Determination of 17<i>α</i>-Methyltestosterone in Freshwater Samples of Tilapia Farming by High Performance Liquid chromatography

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American Journal of Analytical Chemistry 2013年第4期4卷 207-211页

作者： Isabel R. Barbosa Sara Lopes Rhaul Oliveira Inês Domingues Amadeu M. V. M. Soares António J. A. Nogueira Centre for Pharmaceutical Studies Faculty of Pharmacy University of Coimbra Coimbra Portugal Department of Biology & CESAM University of Aveiro Aveiro Portugal Faculty of Pharmacy University of Coimbra Coimbra Portugal

17α-methyltestosterone is used to induce the sex reversal of Tilapia sp. to obtain cultures mono-sex to an economically viable. This practice may lead to environmental contamination and problems in human health. Therefore methods need to be developed to detect residues of 17α-methyltestosterone in aqueous matrices. A simple high-performance liquid chromatographic method using ultraviolet detection (245 nm) and testosterone as internal standard has been developed for the monitoring 17α-methyltestosterone in freshwater samples of tilapia aquaculture. The method described involves limited sample preparation as it includes a filtration followed by a single solid-phase extraction step using C18 cartridge. Validation data indicated that the HPLC-UV method for 17α-methyltestosterone determination in the concentration range of 50 - 2000 μg/L provided good linearity, sensitivity, accuracy and precision. Method performance was efficiently applied to monitoring the freshwater samples of fish ponds and the surrounding aquatic channels.

关键词： 17α-Methyltestosterone High Performance Liquid chromatography Environment Tilapia Farming

Reproduction of peaks distorted and tailing in supercritical fluid chromatography with capillary column

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Reproduction of peaks distorted and tailing in supercritical...

Fabrication and characterization of aligned macroporous monolith for protein high-performance chromatography

30th International Symposium on Capillary chromatography、4th GC×GC Symposium、16th National Symposium and Exhibition on chromatography,i.e. 1st Dalian International Symposium and Exhibition on chromatography

作者： Funazukuri,T. Kagei,S. Department of Applied Chemistry Institute of Science and Engineering Chuo University1-13-27 KasugaBunkyo-kuTokyo 112-8551Japan Faculty of Environment and Information Sciences Yokohama National University 79-7 TokiwadaiHodogaya-kuYokohama 240-8501Japan

＜正＞Supercritical（SC）fluid chromatography,mostly with carbon dioxide as a mobile phase,is used to measure the thermodynamic properties such as retention factor and diffusion coefficient for instance,by the chromatographic impulse response（CIR）*** the entrainer is not added,it is not easy to obtain the symmetrical peaks of polar compounds experimentally even by using various stationary phases,and the reproduction of asymmetric peaks is limited with a linear adsorption model.

关键词： Binary diffusion coefficients chromatography Dispersion model Langmuir Peak reproduction

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Fabrication and characterization of aligned macroporous mono...

Rapid analysis of polymer additives using ultra performance liquid chromatography with PDA and ELS detection

中国化学会第30届学术年会-第二十三分会：复杂样品分离分析

作者： Kaifeng Du Qi Zhang Department of Pharmaceutical & Biological Engineering School of Chemical Engineering Sichuan University

An improved freeze casting method is proposed for the fabrication of aligned macroporous monolith as stationary phase for high speed *** fabrication process includes mainly two steps as ***,the monomer solution is pre-polymerized into colloids and then dispersed within the solvent ***,the suspension is directionally frozen in liquid nitrogen and further solidified to direct the formation of aligned macroporous *** following characterization indicates that the monolith possesses both the obvious aligned macropores and the diffusion *** aligned macroporous monolith is tried as stationary phase for the adsorption *** reveals that the equilibrium adsorption time is about 70 min and the maximum adsorption capacity reaches 33.85 mg mL for IgG and 45.69 mg mL for lysozyme,***,the dynamic adsorption capacity at 50%breakthrough point reaches about 25.5 mg mL of lysozyme and 22.4 mg mL of IgG,***,both dynamic adsorption capacity and column efficiency exhibit no obvious reduction with increasing flow *** these results suggest that the aligned macropores have positive effect on improving the chromatographic ***,it is worth to note that the fabricated aligned macroporous monolith is applicable and can be extended from chromatography to catalysis.

关键词： freeze casting method aligned macropores monolith chromatography

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Rapid analysis of polymer additives using ultra performance ...

Stereoselective separation and determination of quizalofopethyl in tobacco by ultra-performance convergence chromatography with tandem mass spectrometry

作者： Lee,P.J. Di Gioia,A.J. Waters Corporation 34 Maple Street MilfordMA 01757USA Waters Corporation 34 Maple Street MilfordMA 01757USA

＜正＞Polymer and plastic articles play important roles in our daily *** widespread use results not only from the development of new polymer chemistry and resins but also from the advancement of polymer additives. Polymer additives protect and enhance the performance of polymer and plastic products throughout the cycle of manufacturing,processing,storage and final *** additives are used to process polymer resins in order to obtain articles with the desired properties such as color,shape,mechanical strength,as well as resistance to heat,flame,oxidation,aging and light degradation.

关键词： chromatography Quantitative analysis Polymer additive UPLC PDA library matching

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烟草科技 2018年第A1期51卷 38-46页

作者： YANG Fei TANG Gangling FAN Ziyan WANG Ying LIU Shanshan DENG Huimin BIAN Zhaoyang LI Zhonghao Chinn National Tobacco Quality Supervision and Test Center No.2 Fengyang Street Zhengzhou 450001 China

The purpose of this study was to develop and validate a novel and sensitive method for simultaneous enantiomeric analysis of quizalofop-ethyl in tobacco using ultra-performance converge nee chromatography with tandem mass spectrometry(UPC-MS/MS).Sample preparation prior to UPC^2-MS/MS analysis followed a QuEChERS(quick,easy,cheap,effective,rugged and safe)*** UPC^2-MS/MS method used an Acquity UPC2 Trefoil CEL2 column with a mobile phase of CO2 and *** injection volume was 2 μL and run-time was 6 min with the mobile phase running at 2.0 mL/min flow *** temperature,auto back pressure regulator pressure(ABPR),and modifier solvent were optimized for separation *** the optimal conditio ns,the recoveries for all the ena ntiomers were 81.3%-94.8% with relative standard deviations(RSD)less than 5.0% at 0.1,1.0 and 2.0 mg/kg levels,*** coefficients of determination(R^2≥0.993 7)were achieved for all the studied enantiomers in the tobacco over the concentration range of 10-250 ng/*** limits of detection(LODs)varied from 0.02 mg/kg to 0.04 mg/kg,and the limits of quantification(LOQs)were ≤ 0.13 mg/*** results confirm that the proposed method is green,convenient and reliable for the enantioselective determination of the enantiomers of quizalofop-ethyl in tobacco.

关键词： Quizalofop-ethyl Stereoselective separation Herbicide Tandem mass spectrometry Ultraperformance convergence chromatography

Modernization of Chinese herbal compound and the high performance liquid chromatography tandem mass spectrometry (HPLC-MS)

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沈阳药科大学学报 2008年第S1期25卷 119-119页

作者： LI Wen-lan1,2,3,SUN Zhi1,2,DU Juan1,2(1.Engineering Research Center of natural antineoplastic drugs,Ministry of Education,Harbin 150076,China 2.Center of Research and Development on Life Sciences and Environmental Sciences,Harbin University of Commerce,Harbin 150076,China 3.Institute of Materia Medica and Postdoctoral Programme of Harbin University of Commerce,Harbin 150076,China)

Chinese herbal compound is playing an important role on curing human *** it has been a trend that Chinese herbal compound is being used all over the world in 21 ***,our Chinese herbal compound is facing serious challenge for the lack of canonical system of quality criterion for Chinese herbal compound so it has been a urgent problem to set up the quality control standards and reveal therapeutic basis of Chinese herbal *** order to give full play to the advantages of Chinese herbal compound,modern scientific and technological is used to research of Chinese herbal compound,especially the high performance liquid chromatography tandem mass spectrometry(HPLC-MS),because it is high sensitive,rapid,and obtain more *** is very necessary that HPLC-MS is uesed to elucidate the effective components of basic substances of Chinese Herbal Compound,and endow traditional Chinese medicine with modern scientific connotation.

关键词： modernization of Chinese herbal compound the high performance liquid chromatography tandem mass spectrometry(HPLC-MS)

Cation-exchange high-performance liquid chromatography for variant hemoglobins and HbF/A2:What must hematopathologists know about methodology?

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World Journal of Methodology 2016年第1期6卷 20-24页

作者： Prashant Sharma Reena Das Department of Hematology Level 5Research Block APostgraduate Institute of Medical Education and Research

Cation-exchange high-performance liquid chromatography(CE-HPLC) is a widely used laboratory test to detect variant hemoglobins as well as quantify hemoglobins F and A2 for the diagnosis of thalassemia syndromes. It's versatility, speed, reproducibility and convenience have made CE-HPLC the method of choice to initially screen for hemoglobin disorders. Despite its popularity, several methodological aspects of the technology remain obscure to pathologists and this may have consequences in specific situations. This paper discusses the basic principles of the technique, the initial quality control steps and the interpretation of various controls and variables that are available on the instrument output. Subsequent sections are devoted to methodological considerations that arise during reporting of cases. For instance, common problems of misidentified peaks, totals crossing 100%, causes of total area being above or below acceptable limits and the importance of pre-integration region peaks are dealt with. Ultimately, CE-HPLC remains an investigation, the reporting of which combines in-depth knowledge of the biological basics with more than a working knowledge of the technological aspects of the technique.

关键词： Anemia Diagnosis Hematological disorders Hematopathology Hemoglobin Hemoglobinopathies High-performance liquid chromatography Laboratory instrumentation Red blood cells Thalassemia

Study of Cuscuta chinensis Lam. in Nuhuang Fuzheng Oral Liquid by Thin Layer chromatography

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Medicinal Plant 2017年第5期8卷 6-10页

作者： Wengui FU Zhiqiang YAN Shaoqin ZHAI Maixun ZHU Hua ZHENG Xingzhong SUN Chongqing Academy of Animal Sciences Baicheng Center for Animal Disease Control and Prevention

[Objectives] To better control the quality of Nuhuang Fuzheng Oral Liquid and study the main component Cuscuta chinensis *** 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 *** 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.

关键词： Nuhuang Fuzheng Oral Liquid Identification by thin layer chromatography Cuscuta chinensis Lam Quality control