Showing papers in "Journal of Chromatography A in 1978"

TL;DR: In this article, a general expression is derived for the numerical calculation of retention data for the case when the relationship between the capacity factor,k, and the mobile phase composition, φ, is known.

TL;DR: In this paper, a general plate height equation has been derived to express the effect of axial dispersion in the interstitial space, mass transfer resistances at the boundary and in the interior of porous stationary phase particles, and kinetic resistances associated with the reversible binding of eluite by the stationary phase.

TL;DR: In this article, the width of the protein bands, taking into account axial diffusion and axial dispersion by non-uniformity of flow and for the pH at which proteins are expected to emerge from the column, are derived.

TL;DR: In this article, a linear correlation between the logarithm of the capacity factors, measured at an appropriate reference temperature, and the corresponding enthalpies for the particular chromatographic process was found.

TL;DR: In this paper, a quality test procedure for glass capillary columns is described that offers the following information: adsorption of hydroxyl function, adaption of aldehyde function, separation efficiency, acid-base behaviour and film thickness.

TL;DR: The focusing effects in the ion-exchange chromatography of proteins in a pH gradient predicted in Part I have been confirmed experimentally and could be understood in terms of the equations calculated for the width of the protein bands and for the pH of the emerging protein solutions.

TL;DR: In this article, a two-dimensional liquid chromatographic (HPLC) separation technique was proposed, which consists of a first column filled with GPC material, coupled via a loop injection device with a second column containing reversed-phase material.

TL;DR: This method is now being used routinely for the determination of the concentration and ratios of nucleosides in urine from patients with different types of cancer and in chemotherapy response studies.

TL;DR: In this paper, an injector without a septum is proposed for on-column injection of capillary columns, and some examples of applications are given. But the injector is not suitable for injection of volatile substances.

TL;DR: In this article, the effect of temperature in liquid chromatography on pyrocarbon-containing adsorbents is considered in terms of heats of transfer, solvent eluotropic strength, column linear capacities, pressre drops and efficiencies.

TL;DR: In this paper, the influence of the surface coverage of the bonded phase on polar group selectivity in reversed-phase liquid chromatography has been explored, using a series of synthesized n -octy bonded phases.

TL;DR: The accuracy of amino acid analysis by enantiomer labelling is equal or superior to that of hitherto known methods.

TL;DR: The analysis of ionized solutes by high-performance liquid chromatography (HPLC) may be facilitated by the use of ion-pairing agents as discussed by the authors, and a comprehensive listing of reported chromatographic systems, pairing ions and solutes studied is given.

TL;DR: In this paper, the effects of modifier functionality and the chain length of n-alkylchlorosilanes on the surface structure of packings and on their retention behaviour in reversed-phase chromatography were investigated.

TL;DR: The 2,2′-bicinchoninate reagent described previously for sugar detection in liquid chromatography with ethanol as eluent was adapted to an automated borate complex ion-exchange chromatographic system, in which orcinol-sulphuric acid was used for detection as mentioned in this paper.

TL;DR: In this article, the stability of reversed-phase materials towards attack by various bases was tested and it was shown that the retention properties of the alkaloids tested are governed by the structural properties and concentration of the mobile phase bases, whereas the resolution of such systems is strongly influenced by the pH and the p K values of these amines.

TL;DR: In this article, high performance liquid chromatographic separation of the catecholamines epinephrine, norepinephrine, 3,4-dihydroxybenzylamine and dopamine utilizing an isocratic aqueous mobile phase flowing over a bonded octadecylsilane (μBondapak C18) solid phase, with amperometric detection of the eluate.

TL;DR: The recovery efficiencies of XAD resins −2, −4, −7, and −8 and of resin mixtures were measured using distilled water samples containing 13 organic pollutants as mentioned in this paper.

TL;DR: In this paper, a comparison is made between non-polar chemically bonded phases (CBP), pyrocarbon-modified silica gel (PMS) and pyro carbon-modified carbon black (PMCB), showing that the group selectivity is better for PMS (or PMCB) than for CBP.

TL;DR: Physical parameters for Sepharose 4B and 6B gels were calculated from chromatography of two protein mixtures and it was found that molecules with different frictional ratios followed relationships.

TL;DR: In this paper, a new approach to combined liquid chromatograph-mass spectrometry is described, which uses laser vaporization of the LC effluent and molecular beam techniques to transport and ionize the sample.

TL;DR: In this article, the retention behavior of carboxylic acids in reversed-phase and reversed phase ion-pair choromatography on hydrophobic alkyl-modified silica gel was investigated.

TL;DR: In this paper, a new set of conditions, namely, the addition of phosphoric acid to the mobile phase, has been found to have very real advantages in the analysis of underivatised peptides.

TL;DR: In this paper, a procedure for preparing chromatographic sorbents with high specificity for particular substances was described, with the aid of a chiral template molecule functional groups were placed in a highly crosslinked polymer in such a way that they were present in a Chiral cavity in a given stereochemistry.

TL;DR: In this paper, a chemically bonded octadecylsilane stationary phase was successfully prepared on the inner glass surface of a micro-capillary tube of I.D. 60 μm.

TL;DR: In this article, the influence of surface coverage on chromatograpic properties was studied and the capacity ratio and selectivity did not increase continuously with increasing surface coverage and reached maximum at a surface coverage of ca. 2 μmol·m−2 for polar and non-polar solutes.