Stationary phases carbon

Rittenhouse, C.T., and Olesik, S.V., High performance liquid chromatographic evaluation of a low-temperature glassy carbon stationary phases, /. Liq. Chromatogr. Relat. Technol, 19, (17,18), 2997, 1996. 

Figure 24-3 (a) Porous carbon stationary phase (2 p,m thick) on inside wall of fused silica open tubular column. (fc>) Chromatogram of vapors from the headspace of a beer can. obtained with 0.25-mm-diameter x 30-m-long porous carbon column operated at 30°C for 2 min and then ramped up to 160°C at 20°/min. [Courtesy Alltech Associates, State College, PA.]... 

More recently, Engel and Olesik have also concluded that formic acid is a good modifier for carbon dioxide in SFC. The results they obtained on porous glassy carbon stationary phases with 1.5% (w/w) formic acid in CO2 (16) showed that formic acid was effective because of its strong H-bond donor and very weak H-bond acceptor characteristics higher concentrations of formic acid (3%), however, were found to polymerize on the porous glassy carbon surface (17). 

B. J. Clark, Resolution of chiral compounds by HPLC using mobile phase additives and a porous graphitic carbon stationary phase, J. Pharm. Biomed. Anal., 7 1883-1888 (1989). 

J.-P. Mercier, Ph. Morin, M. Dreux and A. Tambute, Liquid chromatography analysis of phosphonic acids on porous graphitic carbon stationary phase with evaporative light-scattering and mass spectrometry detection, J. Chromatogr. A, 849, 197-207 (1999). 

Chaimbault, R et al. Ion pair chromatography on a porous graphitic carbon stationary phase for the analysis of 20 underivatized protein amino acids. J. Chromatogr. A. 2000,... 

I. Clarot, D. Cledat, S. Battu, and P. J. P. Cardot, Chromatographic study of terpene derivatives on porous graphitic carbon stationary phase with P-cyclodextrin as mobile phase modifier, J. Chromatogr. A 903 (2000), 67. 

Liebman et al. (/ 7) detected the glass transition of poly(vinyl chloride) stationary phases by recording the separation of cisitrans isomers as a function of temperature. It was found that no separation could be achieved in the vicinity of Tg while separation was possible both above and below Tg. Similar discontinuities in the plots of relative retention volumes were reported by Yatmunoto et id. 18) for poly carbonate stationary phases of differing molecular weights. 

Water extract analyzed by two-dimensional LC (SEC and RP on porous graphitic carbon stationary phase) with ICP-MS detection. Two Se-containing fractions were isolated and analyzed by nanoESI-MS and MS-MS... 

Analysis of vinclozolin and iprodione in wine can be performed using a GC-ion trap (IT) system with the analytical conditions reported in Table 9.8. By coupling this method and the SPE sample preparation with the use of the porous carbon stationary phase, the analytes can be recovered with toluene, and the LOQs of 50ng/L and 50pg/L for vinclozolin and iprodione, respectively, are achieved (Matisova et al., 1996). An LOQ of 0.50 pg/L is achieved for analysis of metalaxyl in wine (Kakalfkova et al, 1996). 

Recently, graphitized-carbon stationary phases have become available for reversed-phase carbohydrate analysis. They exhibit a stronger hydrophobic interaction than C,g bonded phases. They are also compatible with a high-pH mobile phase, which speeds up mutarotation and prevents peak splitting due to anomer separation. 

Modified-COi mobile phases excel at stereochemical separations, more often than not outperforming traditional HPLC mobile phases. For the separation of diastereomers, silica, diol-bonded sdica, graphitic carbtm, and chiral stationary phases have aU been successfidly employed. For enantiomer separations, the deiivatized polysaccharide, silica-based Chiralcel and Chiralpak chiral stationary phases (CSPs) have been most used, with many apphcations, particularly in pharmaceutical analysis, readily found in the recent hterature (reviewed in Refs. . To a lesser extent, applications employing Pirkle bmsh-type, cyclodexttin and antibiotic CSPs have also been described. In addition, the use of sUica and graphitic carbon stationary phases with chiral modifiers added to the CO2 mobile phase has been reported. 

Figure 22-2 Cross-sectional view of wall-coated, support-coated, and porous-layer columns. Micrograph shows porous carbon stationary phase on inside wall of a fused-silica open tubular column.

Karlsson, A. Berglin, M. Charron, C. Robustness of the chromatographic separation of alprenolol and related substances using silica-based stationary phase and selective retention of metoprolol and related substances on a porous graphitic carbon stationary phase. J. Chromatogr., A 1998, 797, 75 -82. 

Trost A, Kleibohmer W, Cammann K. Liquid chromatographic isolation of coplanar PCB congeners on an activated carbon stationary phase. Fresenius J Ana Chem 1997 359(3) 249-53. 

Xu, J.Q. Aubry, A.-F. Impurity profiling of non-nucleoside reverse transcriptase inhibitors by HPLC using a porous graphitic carbon stationary phase, Chromatographia, 2003, 57, 67-71. 

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