摘要:

Capillary zone electrophoresis (CZE) is an efficient microseparation technique that can be used for the separation of small as well as large biomolecules. The use of micelles in the buffer makes CZE an acceptable technique for the resolution of charged and neutral molecules. The separation of chiral compounds is an important aspect of the pharmaceutical industry, synthetic organic chemistry and other areas. Optical isomers can be separated from each other using high pressure liquid chromatography (HPLC) and capillary gas chromatography (CGC), however, each of these techniques has its limitations. CGC and HPLC require a chiral column, which is costly, CZE does not. CZE has the highest efficiency and chiral separations are achieved by adding a modifier to the buffer that facilitates the separation of optical isomers.

ISSN:1073-9149    

DOI:10.1080/10739149408001183

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A slide-type 2 nL-injector, Nano-injector, was constructed. The performance of Nano-injector was about 30% of hydrostatic injection by the comparison of theoretical plate number; however the relative peak area of drugs in albumin solution was constant compared to the hydrostatic method, vacuum method and electro-migration method. The error was less than 5%.

ISSN:1073-9149    

DOI:10.1080/10739149408001184

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The development of a near-infrared optical fiber detector for the determination of metal ions was investigated. The optical fiber detector consists of a semiconductor laser diode, an optical fiber, an NIR dye and a photodiode detector. Two plastic fibers are connected together with poly(methyl methacrylate) (PMMA) with a reaction phase at the distal common end. The reaction phase had a diameter of about <2 mm. Excitation of the dye/analyte complex was induced with a semiconductor laser diode at 780 nm and the emission intensity signal was collected by two instrument systems. No photobleaching effect was observed during the investigations. The response time for 95% of the signal was less than 5 seconds. The use of plastic fibers has allowed easy immobilization of an NIR dye. The dye was entrapped in a polymer matrix that allows the diffusion of the analyte. Low background signal of the photodiode permitted the detection of dye in the picomolar level. Comparison of the optical fiber results between a PMT and a photodiode was made. The use of smaller components shown here will allow the manufacturing of portable optical fiber detectors for applications in industry, medicine and the environment.

ISSN:1073-9149    

DOI:10.1080/10739149408001185

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The concentration dependence of surface enhanced Raman scattering (SERS) of adsorbed poly-(L-histidine) on surfaces of silver has been investigated. It has been found that the spectral qualities are inversely proportional to the concentrations of solutions applied. Excellent SERS spectral enhancement could be achieved for the sample applied from wt-0.02% solution. This phenomenon was termed as “dilution effect” on SERS spectrum of polymers. The observed phenomena are in accordance with Qian's proposal for the existence of coil shrinkage in dilute solution.

ISSN:1073-9149    

DOI:10.1080/10739149408001186

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A two-stage particle beam LC-MS interface, capable of being coupled to a quadrupole, sector or ion trap mass spectrometer, is described. The device has a modular design, allowing operating parameters to be easily optimized whilst in use. Successful coupling to a quadrupole ion trap mass spectrometer (ITMS) is achieved using a novel heated transfer line for analyte vaporization and scan routines which eliminate solvent ion effects.

ISSN:1073-9149    

DOI:10.1080/10739149408001187

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Two procedure files were created to automate the processing of mass spectral (MS) data files. The procedure file, RJR, was used to set up the sequence of mass spectral data files to be processed, to input the parameters for printout format, and to automatically execute the processing of the mass spectral data files. The other procedure file, RJRAQ, was used to execute the processing of mass spectral data. RJRAQ produced header information of the mass spectral data files and the integration information, generated graphic displays of the total ion chromatogram (TIC), mass spectra, and library search results, and provided hard copies of all textual reports and graphic outputs.

ISSN:1073-9149    

DOI:10.1080/10739149408001188

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739149408001189

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor