Porous graphitized carbon

This Fmoc analog is prepared from the chloroformate, O-succinimide, or p-nitrophenyl carbonate and is cleaved with 10% piperidine in 1 1 6M guanidine/IPA. It was designed to interact strongly on a column of porous graphitized carbon so as to aid in the purification of peptides after cleavage from the resin. 

Zebiihr et al. (29) developed an automated system for determining PAHs, PCBs and PCDD/Fs by using an aminopropyl silica column coupled to a porous graphitic carbon column. This method gives five fractions, i.e. aliphatic and monoaromatic hydrocarbons, polycyclic aromatic hydrocarbons, PCBs with two or more ortho-chlorines, mono-ort/io PCBs, and non-ortho PCBs and PCDD/Fs. This method employed five switching valves and was successfully used with extracts of sediments, biological samples and electrostatic filter precipitates. 

A CSP based on the adsorption of a chiral anthrylamine on porous graphitic carbon successfully resolved the enantiomers of tropic acid derivatives and anti-inflammatory agents in SFC [65]. The carbon-based CSP produced superior results when compared to an analogous silica-based CSP. Occasional washing of the column was necessary to remove highly retained substances. 

Wan, Q.- H., Davies, M. C., Shaw, P. N., and Barrett, D. A., Retention behavior of ionizable isomers in reversed-phase liquid chromatography a comparative study of porous graphitic carbon and octadecyl bonded silica, Anal. Chem., 68, 437, 1996. 

Phenyl (Cohesive Technologies), the polymer-based Oasis HLB (Waters), the Cyclone (Cohesive Technologies), and the porous graphitized carbon-based Hypercarb (ThermoHypersil, Cheshire, UK) Cohesive s 2300 system was the HTLC component. Merck s monolithic reversed-phased Chromolith Speed ROD (RP-C18 (50 x 4.6 mm) served as the analytical column. The Oasis HLB, Cyclone TFC, and Hypercarb yielded the best retention capacity and good elution efficiency and volume. Recovery was 42 to 94% with a sample volume of 10 mL. Run time was 14 min. LODs were 0.4 to 13 ng/L for most compounds. 

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. 

Tornkvist A, Sjoberg PJ, Markides KE, Bergquist J. 2004. Analysis of catecholamines and related substances using porous graphite carbon as separation media in liquid chromatography tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 801 323. 

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

Porous graphitic carbon deposited on silica8 is a stationary phase that exhibits increased retention of nonpolar compounds relative to retention by C18. Graphite has high affinity for polar compounds and separates isomers that cannot be separated on Clg. The stationary phase is stable in 10 M acid and 10 M base. 

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

S. Mazan, G. Cretier, N. Gilon, J.-M. Mermet, and J.-L. Rocca, Porous Graphitic Carbon as Stationary Phase for LC-ICPMS Separation of Arsenic Compounds. Anal. Chem. 2002, 74, 1281. For another robust stationary phase, see C. J. Dunlap, C. V. McNeff, D. Stoll, and P. W. Carr, Zirconia Stationary Phases for Extreme Separations, Anal. Chem. 2001, 73, 599A. 

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. 

The general concepts of EC-Array are described in detail elsewhere (Acworth and Gamache, 1996). Briefly this technique employs up to 16 series EC cells (Fig. 8.6) with porous graphitic carbon-based WEs, similar in concept to those described in... 

Creaser CS, Al-Haddad A. 1989. Fractionation of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans on porous graphitic carbon. Anal Chem 61 1300-1302. 

B. Kaur, The use of porous graphitic carbon in high performance liquid chromatography, LC-GC, 5 468 (1990). 

J. A. Knox, B. Haur, and G. R. Millward, Structure and performance of porous graphitic carbon in liquid chromatography, J. Chromatogr., 3 353 (1986). 

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). 

PCBs Porous graphitic carbon Fractionation of PCBs — [101]... 

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). 

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