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61.
Zamfir A Vukelić Z Bindila L Peter-Katalinić J Almeida R Sterling A Allen M 《Journal of the American Society for Mass Spectrometry》2004,15(11):1649-1657
The introduction of chip-based electrospray (ESI) ion sources into biological mass spectrometry (MS) addressed the fundamental issue of how to analyze minute amounts of complex biological systems. The automation of sample delivery into the MS combined with the chip-based ESI allows for high quality bioanalysis in a high-throughput fashion. These advantages have already been demonstrated in proteomics, direct screening of drugs and drug discovery. As part of our continuing effort to implement automated chip-based mass spectrometry into the field of complex carbohydrate analysis, we hereby report the development of a chipESI MS and MS/MS methodology for the screening of gangliosides. A strategy to characterize a complex ganglioside mixture from human cerebellar tissue, by automated ESIchip-quadrupole time-of-flight (QTOF) MS and MS/MS is presented here. The feasibility of this method, and the general experimental requirements for automated chipESI MS analysis of these carbohydrate species is described. 相似文献
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Oka's principle for holomorphic fiber bundles with sprays 总被引:3,自引:0,他引:3
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Analysis of inorganic ions in cerebrospinal fluid (CSF) is used mainly in the diagnostics of central nervous system diseases, such as Alzheimer’s disease or multiple sclerosis. A new analytical method for fast determination of inorganic cations (ammonium, calcium, magnesium, sodium and potassium) and anions (chloride, sulfate, nitrite and nitrate) in CSF on an electrophoretic microchip was developed in this context. Zone electrophoresis (ZE) separations were performed on the microchip with coupled channels (CC) and contact conductivity detection. Two different propionate background electrolytes were used for the sequential determination of cations at pH 3.1 and anions at pH 4.3. ZE was used for the determination of cationic constituents while ZE–ZE approach was employed for the determination of chloride in the first separation channel on the CC microchip and other anionic micro-constituents in the second channel. LOD values were in the range of 0.003–0.012 mg L?1 and 0.019–0.047 mg L?1 for cations and anions, respectively. Repeatability of migration time was up to 1.2 % for both cations and anions. Repeatability of peak area ranged from 0.3 to 5.6 % for cations and from 0.6 to 6.0 % for anions. Recovery of both cations and anions was in the range 90–106 %. CSF samples were only diluted appropriately without other sample pretreatment prior to analysis. Developed sequential method is suitable for fast determination of the studied cations and anions in CSF with total analysis time <15 min. 相似文献
66.
Kirsi S. Mikkonen Jasna S. Stevanic Catherine Joly Patrice Dole Kari Pirkkalainen Ritva Serimaa Lennart Salmén Maija Tenkanen 《Cellulose (London, England)》2011,18(3):713-726
Two future wood biorefinery products, spruce galactoglucomannans (GGM) and microfibrillated spruce wood cellulose (MFC), were
mixed to form composite films. The films were plasticized with different amounts of glycerol, and the preparation of films
was successful even with low glycerol contents. The film properties were studied using optical microscopy and scanning electron
microscopy, x-ray diffraction, water sorption, dielectric analysis, moisture scanning dynamic mechanical analysis, and tensile
testing. The addition of MFC clearly affected the properties of the films by decreasing the moisture uptake and increasing
the relative humidity of softening of the films and by increasing the glass transition temperature, tensile strength, and
Young’s modulus of the films. The effect of MFC addition on the tensile properties of films was emphasized at low glycerol
contents. The addition of MFC did not affect the degree of crystallinity of GGM in the films, which was between 20 and 25%.
MFC can be efficiently used as reinforcement of GGM films to form wood-based composite materials and to prepare GGM-based
films and coatings with low plasticizer content. 相似文献
67.
In most clinical and nutritional studies, it is of significance to know information about the multielemental composition of biological samples. Conventional analysis of biological samples relies upon sample digestion followed by atomic spectrometry detection. This approach is essential for the quantification of ultratrace elements in biological samples. While in other applications it could be of interest to have simpler analytical methods with multielemental capability but involving a minimum sample treatment, reduce the amount of sample and a more cost-effective analysis. In the present contribution, the possibilities and drawbacks of simple sample treatments (i.e., dilution and suspension) in combination with total reflection X-ray fluorescence spectrometry (TXRF) for the analysis of different types of biological samples have been critically evaluated. For that, a set of reference materials or well-characterized biological human fluids (blood, serum, plasma and seminal plasma) and animal/vegetal tissues have been used to estimate the analytical capabilities in terms of limits of detection, trueness and precision of the proposed TXRF methods. The results are based on the authors' experience in analysing biological samples using TXRF, and it is expected that they can be useful for new TXRF users in this field and they can provide a good basis for further application of this technique in clinical studies and other applications dealing with the analysis of biological samples in the future. 相似文献
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Marguí Eva Jablan Jasna Gerić Marko Inić Suzana Domijan Ana-Marija Janušić Renato Šarčević Božena Queralt Ignasi Garaj-Vrhovac Verica 《Analytical and bioanalytical chemistry》2019,411(8):1659-1670
Analytical and Bioanalytical Chemistry - Multielemental analysis of whole blood can provide significant information for the evaluation of nutritional status and diagnosis of certain diseases as... 相似文献
70.
A catalytic asymmetric synthesis of (+)-aza-galacto-fagomine (AGF) – the most promising compound for the pharmacological chaperone therapy of Krabbe disease – was accomplished in six steps, in 14% overall yield. The synthesis hinges on the combination of organocatalyzed aldolization and reductive hydrazination. 相似文献