检索结果-内蒙古大学图书馆

An integrated microfabricated device for dual microdialysis and on-line ESI ion trap mass spectrometry for analysis of complex biological samples

引用

ANALYTICAL CHEMISTRY 1999年第8期71卷 1485-1490页

作者： Xiang, F Lin, YH Wen, J Matson, DW Smith, RD Pacific NW Natl Lab Environm Mol Sci Lab Richland WA 99352 USA

A microfabricated dual-microdialysis device in a single integrated microfabridated platform was constructed using laser micromachining techniques for the rapid fractionation and cleanup of complex biological samples. On-line dual microdialysis and ESI-MS of biological samples was demonstrated using an ion trap mass spectrometer. The mass spectra obtained demonstrated the efficiency of dual microdialysis for removing both high-molecular-weight and low-molecular-weight species that interfere with effective ESI-MS analysis of target biopolymers. Signal-to-noise ratios were also greatly improved compared to direct sample infusion. In addition to its compactness, negligible dead volume, and robustness, the device can be used at a now rate of only 200 nL/min, an order of magnitude lower than that obtained previously. This reduced sample consumption and improved sensitivity with ESI-MS. The results suggest the potential for integration of such microfabricated devices with other sample manipulations for the rapid ESI-MS analysis of complex biological samples.

关键词：大肠杆菌/化学质谱分析法/仪器和设备微透析/仪器和设备分子量联机系统

来源：评论

学校读者我要写书评

暂无评论

Integration of microfabricated devices to capillary electrophoresis-electrospray mass spectrometry using a low dead volume connection: Application to rapid analyses of proteolytic digests

引用

ANALYTICAL CHEMISTRY 1999年第15期71卷 3036-3045页

作者： Li, JJ Thibault, P Bings, NH Skinner, CD Wang, C Colyer, C Harrison, J Natl Res Council Canada Inst Biol Sci Ottawa ON K1A 0R6 Canada Univ Alberta Dept Chem Edmonton AB T6G 2G2 Canada

This report describes the development of a compact and versatile, micromachined chip device enabling the efficient coupling of capillary electrophoresis to electrospray mass spectrometry (CE-ESMS). On-chip separation provides a convenient means of achieving rapid sample cleanup and resolution of multicomponent samples (typically 2-5 min) prior to mass spectral analysis. A low dead volume connection facilitating the coupling of microfabricated devices to CE-ESMS was evaluated using two different interfaces. The first configuration used disposable nanoelectrospray emitters directly coupled to the chip device via this low dead volume junction, thereby providing rapid separation of complex protein digests. The performance of this interface was compared with that of more traditional configurations using a sheath now CE-ESMS arrangement where a fused-silica capillary of varying length enabled further temporal resolution of the multicomponent samples. The sensitivity and analytical characteristics of these interfaces were investigated in both negative and positive ion modes using standard peptide mixtures. The separation performance for synthetic peptides using a chip coated with amine reagent ranged from 26 000 to 58 000 theoretical plates for a sheath flow CE-ESMS interface comprising a 15-cm CE column. Replicate injections of a dilution series of peptide standards provided detection limits of 15-400 nM without the use of on-line preconcentration devices. The reproducibility of migration time ranged from 0.9 to 1.5% RSD wheras RSDs of 5-10% were observed on peak areas. The application of these devices for the analysis of protein digests was further evaluated using on-line tandem mass spectrometry.

关键词：氨基酸序列电泳毛细管/仪器和设备电泳毛细管/方法外源凝集素类/化学外源凝集素类/代谢质谱分析法/仪器和设备质谱分析法/方法分子序列数据蛋白质类/分析蛋白质类/化学蛋白质类/代谢敏感性与特异性序列分析胰蛋白酶/化学胰蛋白酶/代谢

来源：评论

学校读者我要写书评

暂无评论

Microfabricated devices for capillary electrophoresis-electrospray mass spectrometry

引用

ANALYTICAL CHEMISTRY 1999年第15期71卷 3258-3264页

作者： Zhang, B Liu, H Karger, BL Foret, F Northeastern Univ Barnett Inst Boston MA 02115 USA Northeastern Univ Dept Chem Boston MA 02115 USA

Two fundamental approaches for the coupling of microfabricated devices to electrospray mass spectrometry (ESI-MS) have been developed and evaluated. The microdevices, designed for electrophoretic separation, were constructed from glass by standard photolithographic/wet chemical etching techniques. Both approaches integrated sample inlet ports, preconcentration sample loops, the separation channel, and a port for ESI coupling. In one design, a modular, reusable microdevice was coupled to an external subatmospheric electrospray interface using a liquid junction and a fused silica transfer capillary. The transfer capillary allowed the use of an independent electrospray interface as well as fiber optic UV detection. In the second design, a miniaturized pneumatic nebulizer was fabricated as an integral part of the chip, resulting in a very simple device, The on-chip pneumatic nebulizer provided control of the flow of the electrosprayed liquid and minimized the dead volume associated with droplet formation at the electrospray exit port. Thus, the microdevice substituted for a capillary electrophoresis instrument and an electrospray interface-traditionally two independent components. This type of microdevice is simple to fabricate and may thus be developed either as a part of a reusable system or as a disposable cartridge, Both devices were tested on CE separations of angiotensin peptides and a cytochrome c tryptic digest. Several electrolyte systems including a transient isotachophoretic preconcentration step were tested for separation and analysis by an ion trap mass spectrometer.

关键词：氨基酸序列血管紧张素类/分析细胞色素c组/分析电泳毛细管/仪器和设备电泳毛细管/方法设备设计质谱分析法/仪器和设备质谱分析法/方法分子序列数据肽类/分析

来源：评论

学校读者我要写书评

暂无评论

Infrared multiphoton dissociation in an external ion reservoir

引用

ANALYTICAL CHEMISTRY 1999年第11期71卷 2067-2070页

作者： Hofstadler, SA Sannes-Lowery, KA Griffey, RH Ibis Pharmaceut Carlsbad CA 92008 USA

In this work we present a novel scheme for performing infrared multiphoton dissociation (IRMPD) external to the mass analyzer in an external ion reservoir consisting of an rf-only multipole and a pair of electrostatic lens elements. Ions generated by electrospray ionization (ESI) are accumulated in an rf-only hexapole and dissociated by irradiation at 10.6 mu m from a CW CO2 laser in the source region of the mass spectrometer. This scheme is unique from other IRMPD schemes as dissociation occurs in a spatially distinct region of the spectrometer and is independent of the mass spectrometry platform used to analyze the fragment ions. The effectiveness of the technique is demonstrated with ESI IRMPD FTICR mass spectrometry of a 20-mer phosphorothioate oligonucleotide. A comparison of the external IRMPD scheme with nozzle-skimmer dissociation and conventional in-cell IRMPD reveals a significant improvement in signal-to-noise ratio and fragment yield, particularly for larger, more highly charged fragment ions.

关键词：离子激光质谱分析法/仪器和设备质谱分析法/方法谱学傅里叶变换红外/仪器和设备谱学傅里叶变换红外/方法硫代核苷酸类/分析硫代核苷酸类/化学

来源：评论

学校读者我要写书评

暂无评论

Simultaneous determination of trace benzodiazepines from drinks by using direct electrospray probe/mass spectrometry (DEP/MS)

引用

FORENSIC SCIENCE INTERNATIONAL 1999年第2期103卷 79-88页

作者： Chen, YC Hu, AR Tzu Chi Coll Med & Humanities Inst Toxicol Hualien 970 Taiwan Tzu Chi Coll Med & Humanities Dept Med Technol Hualien 970 Taiwan

This study presents a novel means of rapidly determining benzodiazepines in various drinks. Electrospray mass spectrometry with a direct probe design is used as the analytical instrument. Samples are treated only by a simple liquid-liquid extraction prior to direct electrospray probe/mass spectrometry (DEP/MS) analysis. The proposed method provides a relatively easy and efficient means of identifying the drugs in a very short time interval. On average, sample analysis is completed in less than five minutes including sample pretreatment. It is especially useful in forensic science since the technology can provide a rapid identification for unknown samples. Thus, the method proposed herein is highly appropriate for rapidly screening a large number of samples. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.

关键词：啤酒/分析苯二氮|艹卓|类/分析饮料/分析碳酸盐饮料/分析柑橘属法医学/方法质谱分析法/仪器和设备质谱分析法/方法茶/化学

来源：评论

学校读者我要写书评

暂无评论

Nanoelectrospray -: More than just a minimized-flow electrospray ionization source

引用

JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 1999年第4期10卷 300-308页

作者： Juraschek, R Dülcks, T Karas, M Univ Frankfurt Div Instrumental Analyt Chem D-60590 Frankfurt Germany

The comparison between electrospray ionization (ESI) mass spectra from NaCl solutions with and without analyte obtained under ionspray and nanospray conditions reveals different mass spectral behavior of the two ESI techniques. This can be attributed to the different initial droplet sizes which are in the mu m range for ionspray, while in nanospray they are believed to be about one order of magnitude smaller. In the context of the widely accepted uneven-fission model, nanospray would then enter one fission generation later;in addition, a higher initial droplet surface charge density in nanospray results in early fissions without extensive evaporation and thus increase in sample and salt concentration. This rationalizes that ionspray spectra closely resemble nanospray spectra from solutions with about one order of magnitude higher salt concentrations, showing a higher tolerance of nanospray towards salt contamination. When the analyte is a peptide tin a solution containing a high molar surplus of salt), molecule ion formation effectively competes with salt cluster ion formation;when the analyte is a sugar, it is detectable beside a high salt concentration only with nanospray, indicating the supporting effect of surface activity on ion release in the case of peptides. A model is presented which explains the different mass spectral behaviour of ionspray and nanospray by suggesting different "predominant fission pathways" depending on the size of the initial droplets. (C) 1999 American Society for Mass Spectrometry.

关键词：算法化学物理胰岛素/化学质谱分析法/仪器和设备药用溶液氯化钠/化学

来源：评论

学校读者我要写书评

暂无评论

Preliminary investigation of electrothermal vaporization sample introduction for inductively coupled plasma time-of-flight mass spectrometry

引用

ANALYTICAL CHEMISTRY 1999年第7期71卷 1378-1383页

作者： Mahoney, PP Ray, SJ Li, GQ Hieftje, GM Indiana Univ Dept Chem Bloomington IN 47405 USA

The coupling of an electrothermal vaporization (ETV) apparatus to an inductively coupled plasma time-of-flight mass spectrometer (ICP-TOFMS) is described. The ability of the ICP-TOFMS to produce complete elemental mass spectra at high repetition rates is experimentally demonstrated. A signal-averaging data acquisition board is employed to rapidly record complete elemental spectra throughout the vaporization stage of the ETV temperature cycle;a solution containing 34 elements is analyzed. The reduction of both molecular and atomic isobaric interferences through the temperature program of the furnace is demonstrated. Isobaric overlaps among the isotopes of cadmium, tin, and indium are resolved by exploiting differences in the vaporization characteristics of the elements. Figures of merit for the system are defined with several different data acquisition schemes capable of operating at the high repetition rate of the TOF instrument. With the use of both ion counting and a boxcar averager, the dynamic range is shown to be linear over a range of at least 6 orders of magnitude. A pair of boxcar averagers are used to measure the isotope ratio for silver with a precision of 1.9% RSD, despite a cycle-to-cycle precision of 19% RSD, Detection limits of 10-80 fg are calculated for seven elements, based upon a 10-mu L injection.

关键词：质谱分析法/仪器和设备质谱分析法/方法

来源：评论

学校读者我要写书评

暂无评论

HPLC atmospheric pressure chemical ionization mass spectroscopy of eight regulated sulfonamides

引用

JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS 1999年第3-4期19卷 301-308页

作者： Combs, MT Ashraf-Khorassani, M Taylor, LT Virginia Tech Dept Chem Blacksburg VA 24061 USA

Reversed phase high performance liquid chromatogaphy coupled with on-line atmospheric pressure chemical ionization mass spectrometry, HPLC/APCI-MS, has been applied to a mixture of eight sulfonamides. In full scan mode, extracted ion chromatograms produced minimum detectable quantities (MDQ) of 0.8 ng on column, for six of the eight regulated sulfonamides investigated. Selected ion monitoring yielded a 50 pg MDQ for sulfamerazine, sulfadiazine and sulfamethazine, while, the other compounds presented higher values. Analysis of supercritical fluid extracts of chicken liver containing sulfadimethoxine were found to be easily detected by HPLC/APCI-MS. In extracts of chicken liver spiked with 25 mu g kg(-1) (25 ppb) of sulfadimethoxine this compound could be detected in selected ion mode, while 100 pg mu l(-1) was detectable in either full scan or single ion modes. The analysis method for extracted sulfadimethoxine also demonstrated good linearity and reproducibility in both single ion and scan mode. (C) 1999 Elsevier Science B.V. All rights reserved.

关键词：抗感染药/分析大气压鸡色谱法高压液相/仪器和设备利尿药/分析评价研究(主题) 离子肝/化学肝提取物/分析质谱分析法/仪器和设备质谱分析法/方法质谱分析法/标准结果可重复性敏感性与特异性磺胺类/分析动物

来源：评论

学校读者我要写书评

暂无评论

LC/MS applications in drug development

引用

MASS SPECTROMETRY REVIEWS 1999年第3-4期18卷 187-279页

作者： Lee, MS Kerns, EH Milestone Dev Serv Pennington NJ 08534 USA

The combination of high-performance liquid chromatography and mass spectrometry (LC/MS) has had a significant impact on drug development over the past decade. Continual improvements in LC/MS interface technologies combined with powerful features for structure analysis, qualitative and quantitative, have resulted in a widened scope of application. These improvements coincided with breakthroughs in combinatorial chemistry, molecular biology, and an overall industry trend of accelerated development. New technologies have created a situation where the rate of sample generation far exceeds the rate of sample analysis. As a result, new paradigms for the analysis of drugs and related substances have been developed. The growth in LC/MS applications has been extensive, with retention time and molecular weight emerging as essential analytical features from drug target to product. LC/MS-based methodologies that involve automation, predictive or surrogate models, and open access systems have become a permanent fixture in the drug development landscape. An iterative cycle of "what is it?" and "how much is there?" continues to fuel the tremendous growth of LC/MS in the pharmaceutical industry. During this time, LC/MS has become widely accepted as an integral part of the drug development process. This review describes the utility of LC/MS techniques for accelerated drug development and provides a perspective on the significant changes in strategies for pharmaceutical analysis. Future applications of LC/MS technologies for accelerated drug development and emerging industry trends are also discussed. (C) 1999 John Wiley & Sons, Inc.

关键词：氨基酸序列生物药学化学药物色谱法液相/仪器和设备色谱法液相/方法质谱分析法/仪器和设备质谱分析法/方法分子序列数据工艺学制药人类

来源：评论

学校读者我要写书评

暂无评论

Applications of mass spectrometry to signal transduction

引用

PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY 1999年第3-4期71卷 501-523页

作者： Resing, KA Ahn, NG Univ Colorado Dept Chem & Biochem Boulder CO 80309 USA Univ Colorado Howard Hughes Med Inst Boulder CO 80309 USA

Advances in mass spectrometry instrumentation, protocols for sample handling, and computational methods provide powerful new approaches to solving problems in analytical biochemistry. This review summarizes recent work illustrating ways in which mass spectrometry has been used to address questions relevant to signal transduction. Rather than encompass all of the instruments or methodologies that might be brought to bear on these problems, we present an overview of commonly used techniques, promising new methodologies, and some applications. (C) 1999 Elsevier Science Ltd. All rights reserved.

关键词：生物化学/方法脂类/分析脂类/生理学质谱分析法/仪器和设备质谱分析法/方法蛋白质构象蛋白质折叠蛋白质加工转译后蛋白质类/化学蛋白质类/代谢信号传导动物人类

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：