Chromatography, capillary

Figure 9.5 The generic setup for two-dimensional liquid chromatography-capillary zone electrophoresis as used by Jorgenson s group. The LC separation was performed in hours, while the CZE runs were on a time scale of seconds.

MICROCOLUMN REVERSE PHASE HIGH PEREORMANCE LIQUID CHROMATOGRAPHY-CAPILLARY ZONE ELECTROPHORESIS... 

Figure 9.6 Surfer-generated chromatoeletropherogram of fluorescamine-labeled tryptic digest of ovalbumin. Reprinted from Analytical Chemistry, 62, M. M. Bushey and J. W. Jorgenson, Automated instrumentation for comprehensive two-dimensional high-performance liquid chromatography/capillary zone electrophoresis, pp 978-984, copyright 1990, with permission from the American Chemical Society.

J. P. Larmann-Jr, A. V. Lemmo, A. W. Moore and J. W. Jorgenson, Two-dimensional sep-ar ations of peptides and proteins by comprehensive liquid chromatography-capillary electrophoresis . Electrophoresis 14 439-447 (1993). 

An on-line supercritical fluid chromatography-capillary gas chromatography (SFC-GC) technique has been demonstrated for the direct transfer of SFC fractions from a packed column SFC system to a GC system. This technique has been applied in the analysis of industrial samples such as aviation fuel (24). This type of coupled technique is sometimes more advantageous than the traditional LC-GC coupled technique since SFC is compatible with GC, because most supercritical fluids decompress into gases at GC conditions and are not detected by flame-ionization detection. The use of solvent evaporation techniques are not necessary. SFC, in the same way as LC, can be used to preseparate a sample into classes of compounds where the individual components can then be analyzed and quantified by GC. The supercritical fluid sample effluent is decompressed through a restrictor directly into a capillary GC injection port. In addition, this technique allows selective or multi-step heart-cutting of various sample peaks as they elute from the supercritical fluid... 

Figure 12.20 SFC-GC analysis of a sample of aviation fuel (a) SFC separation into two peaks (b and c) coixesponding GC ttaces of the respective peaks (flame-ionization detection used throughout). Reprinted from Journal of High Resolution Chromatography, 10, J. M. Levy et ah, On-line multidimensional supercritical fluid chromatography/capillary gas chromatography , pp. 337-341, 1987, with permission from Wiley-VCH.

J. M. Eevy, J. P. Guzowski and W. E. Huhak, On-line multidimensional superaitical fluid chromatography/capillary gas chromatography. J. High Resolut. Chromatogr. 10 337-341 (1987). 

Senorans, R J., Reglero, G., and Herraiz, M., Use of a programmed temperature injector for on-line reversed-phase liquid chromatography-capillary gas chromatography, /. Chromatogr Sci, 33, 446, 1995. 

Principles and Characteristics As mentioned already (Section 3.5.2) solid-phase microextraction involves the use of a micro-fibre which is exposed to the analyte(s) for a prespecified time. GC-MS is an ideal detector after SPME extraction/injection for both qualitative and quantitative analysis. For SPME-GC analysis, the fibre is forced into the chromatography capillary injector, where the entire extraction is desorbed. A high linear flow-rate of the carrier gas along the fibre is essential to ensure complete desorption of the analytes. Because no solvent is injected, and the analytes are rapidly desorbed on to the column, minimum detection limits are improved and resolution is maintained. Online coupling of conventional fibre-based SPME coupled with GC is now becoming routine. Automated SPME takes the sample directly from bottle to gas chromatograph. Split/splitless, on-column and PTV injection are compatible with SPME. SPME can also be used very effectively for sample introduction to fast GC systems, provided that a dedicated injector is used for this purpose [69,70],... 

Schure (1999) has studied the effect of multidimensional dilution for column-based separations that incorporate chromatography, capillary electrophoresis (CE), and FFF. In all of these cases, the dilution factors are multiplicative this gives the direct result that the limit of detection for MDC is... 

Schure, M.R. (1999). Limit of detection, dilution factors, and technique compatibility in multidimensional chromatography, capillary electrophoresis, and field-flow fractionation. Anal. Chem. 71, 1645-1657. 

Rowe, K., Bowlin, D., Zou, M., Davis, J.M. (1995). Application of 2-D statistical theory of overlap to three separation types 2-D thin-layer chromatography, 2-D gas chromatography, and liquid chromatography/capillary electrophoresis. Anal. Chem. 67, 2994. 

Lemmo, A.V., Jorgenson, J.W. (1993a). Two-dimensional protein separation by microcolumn size-exclusion chromatography-capillary zone electrophoresis. J. Chromatogr. A 633(1-2), 213-220. 

Bergstrom, S.K., Samskog, J., Markides, K.E. (2003). Development of a poly(dimethylsilox-ane) interface for on-line capillary column liquid chromatography-capillary electrophoresis coupled to sheathless electrospray ionization time-of-flight mass spectrometry. Anal. Chem. 75, 5461-5467. 

Ehala, S., Kaljurand, M., Kudrjashova, M., Vaher, M. (2004). Stroboscopic sampling in comprehensive high-performance liquid chromatography-capillary electrophoresis via a pneumatic sampler. Electrophoresis 25, 980-989. 

He, Y., Yeung, E.S., Chan, K.C., Issaq, HJ. (2002). Two-dimensional mapping of cancer cell extracts by liquid chromatography-capillary electrophoresis with ultraviolet absorbance detection. J. Chromatogr. A 979, 81-89. 

Issaq, H.J., Chan, K.C., Cheng, S.L., Qingho, L. (2001). Multidimensional high performance liquid chromatography-capillary electrophoresis separation of a protein digest an update. Electrophoresis 22, 1133-1135. 

Janini, G.M., Chan, K.C., Conrads, T.P., Issaq, H.J., Veenstra, T.D. (2004). Two-dimensional liquid chromatography-capillary zone electrophoresis—sheathless electrospray ionization-mass spectrometry evaluation for peptide analysis and protein identification. Electrophoresis 25, 1973-1980. 

CL reactions can be coupled as a detection technique in chromatography, capillary electrophoresis, or immunoassay, providing qualitative and/or quantitative information of a large variety of species in the gas and liquid phases. 

Several modes of capillary electrophoretic separation are available ordinary CE, capillary zone electrophoresis, capillary electrokinetic chromatography, capillary gel electrophoresis, capillary electrochromatography, capillary isota-chophoresis, and capillary isoelectric focusing. The different separation mechanisms make it possible to separate a wide variety of substances depending on their mass, charge, and chemical nature.53... 

EPA. 1990a. Chlorinated hydrocarbons by gas chromatography capillary column technique. Method 8121. Washington, DC U.S. Environmental Protection Agency, 1-21. 

See also Gas chromatography Capillary gel electrophoresis (CGE), in microfluidic assays, 26 971 Capillary hydrodynamic flow (CHDF) techniques, 16 291 20 381 Capillary microfiltration/ultrafiltration (MF/UF) technology, 26 83-84 Capillary number, 11 746 Capillary optics, 26 438 Capillary pumped loops (CPLs),... 

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