Porous graphitic carbon HPLC

Besides silica, silica-based and polymeric stationary phases, porous graphitized carbon (PGC), zirconium oxide and its derivatives, alumina and its derivatives have been used for the solution of special separation problems which cannot be easily solved by using traditional HPLC stationary phases. 

Bassler BJ, Hartwick RA. 1989. The application of porous graphitic carbon as an HPLC stationary phase. J Chromatogr Sci 27(4) 162-165. 

P. Ross, Porous Graphitic Carbon in HPLC, LCCC 2000,18. 18 ... 

In addition to high-performance liquid chromatography (HPLC), the chiral resolution using CMPAs was also carried out by supercritical fluid chromatography (SFC) [91] and capillary electrochromatography (CEC) [92-98]. Salvador et al. [91] used dimethylated /1-cyclodextrin as the mobile phase additive on porous graphite carbon as the solid phase for the chiral resolution of tofizopam, warfarin, a benzoxazine derivative, lorazepam, flurbiprofen, temazepam, chlorthalidone, and methyl phehydantoin by SFC. The authors also studied the effect of the concentration of dimethylated /1-cyclodextrin, the concentration of the mobile phase, the nature of polar modifiers, outlet pressure, and the column temperature on the chiral resolution. 

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). 

Se-enriched yeast Water extraction 2-DE (SEC followed by HPLC on porous graphite carbon column) ICP-MS, nanoESI-MS-MS... 

Other methodologies. Desportes et al. (2000) isolated several small wine peptides (Mr <3000) using RP-HPLC on a porous graphite carbon Hypercarb column. The purity of the fractions collected was confirmed by free-solution capillary electrophoresis (FSCE). In a later study, Desportes et al. (2001) determined the peptide sequence of some isolated peptides by Edman degradation. 

Porous graphitic carbon (PGC) has a rigid structure, is chemically stable and has a very hydrophobic surface. It can therefore be used for reversed-phased HPLC, where it displays a similar or greater degree of retention to ODS. It has excellent pH stability and hence ion suppression of either acidic or basic drugs is easily carried out on this material. It displays different selectivity to silica based packings, allowing isomeric separations more typical of unmodified silica to be carried out (Bassler, 1989). 

The discrepancies with the HPLC method are probably due to the imperfect nature of the C18-silica columns. Some of the new-generation reverse-phase materials, such as C18-alumina, polymeric C18, ultra-high carbon-loaded CT8, and porous graphitic carbon may overcome these problems. A recent development is an immobilized artificial membrane (lAM) column, which should more closely model the biological membranes. 

Mazan, S., Cretier, G., Gilon, N., Mermet, J. M., Rocca, J. L. Porous graphitic carbon as stationary phase for LC-ICPMS separation of arsenic compounds in water. Anal Chem 2002, 74, 1281-1287. Bissen, M., Frimmel, F. H. Speciation of As(III), As(V), MMA and DMA in contaminated soil extracts by HPLC-ICP/MS. Fresenius J Anal Chem 2000, 367, 51-55. 

Hong C-S, Bush B, Xiao J. 1992a. Isolation and determination of mono-ortho and non-ortho substituted PCBs (coplanar PCBs) in human milk by HPLC porous graphitic carbon and GC-ECD. Chemosphere 24(4) 465 73. 

A wide variety of native and derivatized CyDs are available for use as mobile phase additives in HPLC. In liquid chromatography to study the interaction of CyDs with guest molecules, the information about cydodextrin adsorption on the stationary phase is very substantial. It should be noted that the separation ability of bonded CyDs and CyDs added to the mobile phase in HPLC is not always the same (see below). To assess the adsorption of CyDs on the stationary phase, the chromatographic properties of native and permethylated CyDs applied in RP18 and porous graphitic carbon (PGC) column have been studied [25-29]. On the RP18 column the adsorption of yS-CyD is much stronger than that of a- or y-CyDs. On the PGC, the order of elution is a- < < y-CyD, in accordance with the increase of... 

HPLC has become the most popular chromatographic technique in drug analysis. A hterature survey reveals a number of papers that take advantage of the benefits of porous graphitized carbon columns for the separation and determination of several compounds of pharmaceutical interest. In particular, this material possesses several advantages, most notably its physical and chemical stabi-hty, as well as a highly stereoselective surface able to resolve diastereomers and geometric isomers also, it is most applicable to the separation of small ionizable molecules that are not retained with octadecylsiloxane (ODS) columns. 

A further example for the analysis of trace levels of pollutants is the determination of polychlorinated dibenzo-dioxins and polychlorinated dibenzofurans in milk. The method includes gel permeation chromatography, alumina cleanup, and porous graphitized carbon chromatography, followed by analysis by GC/high-resolution MS. Moreover, the potential of porous graphitic carbon as an HPLC adsorbent for the isolation of halogenated aromatic compounds has been demonstrated by the fractionation of polychlorinated biphenyls (PCBs), chlorinated pesticides, polychlorinated dibenzo-p-dioxins (PCDDs), and... 

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