Capillary gas adsorption chromatography

In-situ chemical investigation of a comet nucleus by gas chromatography: Porous layer open tubular columns for the separation of light, volatile compounds

“…The corresponding peaks do not, however, have a Gaussian profile, irrespective of the column and compounds studied, even if the amount of sample injected was close to the detection limit. This peak distortion can be explained thermodynamically by column overloading [20 22]; this was expected, because commercial columns are known to have poor sample capacity as was observed by Berezkin et al [23] for alumina PLOT columns.…”

The Column in Gas Chromatography

“…Like all techniques its growth has been cyclic and at the moment it is enjoying an upward trend catalyzed by a maturing of the commercialization of column technology in gas-liquid chromatography, the commercialization of new sorbents and porous-layer open tubular columns for gas-solid chromatography and the realization that modified adsorbents provide greater scope for adjusting selectivity than can be obtained using bulk liquids [8, [272][273][274][430][431][432][433][434]. Like all techniques its growth has been cyclic and at the moment it is enjoying an upward trend catalyzed by a maturing of the commercialization of column technology in gas-liquid chromatography, the commercialization of new sorbents and porous-layer open tubular columns for gas-solid chromatography and the realization that modified adsorbents provide greater scope for adjusting selectivity than can be obtained using bulk liquids [8, [272][273][274][430][431][432][433][434].…”

“…Preliminary treatment of the adsorbent may be used to reduce their number. Very efficient micropacked [465,466] and porous-layer open tubular columns [432][433][434]467] have been prepared with liquid-modified graphitized carbon blacks for separations requiring large numbers of theoretical plates. However, even after such treatment further modification of the surface by the addition of small quantities of liquids that are capable of establishing strong interactions with residual active sites is generally required [459][460][461].…”

Fundamental Relationships of Chromatography

“…[50,[123][124][125][126][127][128][129][130]. In most cases the kinetic variables are evaluated from the coefficients of the van Deemter equation and relate the column plate height to the properties of the mobile phase, particle size or column radius (open tubular columns) and film thickness.…”