Phases In Gas-liquid Chromatography Research Articles

Lack of evidence for dispersive interaction between polycyclic aromatic hydrocarbons and stationary phases in gas‐liquid chromatography

Journal of High Resolution ChromatographyVolume 6, Issue 7 p. 390-391 Short Communication Lack of evidence for dispersive interaction between polycyclic aromatic hydrocarbons and stationary phases in gas-liquid chromatography H. Lamparczyk, H. Lamparczyk Faculty of Pharmacy, K. Marksa 107, 80–416 Gdańsk, PolandSearch for more papers by this authorA. Radecki, A. Radecki Faculty of Pharmacy, K. Marksa 107, 80–416 Gdańsk, PolandSearch for more papers by this author H. Lamparczyk, H. Lamparczyk Faculty of Pharmacy, K. Marksa 107, 80–416 Gdańsk, PolandSearch for more papers by this authorA. Radecki, A. Radecki Faculty of Pharmacy, K. Marksa 107, 80–416 Gdańsk, PolandSearch for more papers by this author First published: July 1983 https://doi.org/10.1002/jhrc.1240060712Citations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume6, Issue7July 1983Pages 390-391 RelatedInformation

Solubility factors for 240 solutes and 207 stationary phases in gas-liquid chromatography

Solubility factors for 240 solutes and 207 stationary phases in gas-liquid chromatography

Correlation of two criteria of polarity for stationary phases in gas-liquid chromatography

Linear relationships between the partial molar excess Gibbs function of a solute methylene group, Δ G E(CH 2), and the average McReynolds constant, ΔI, and between Δ G E(CH 2) and the individual McReynolds constants were determined for a set of 55 liquid stationary phases. All these relationships were identical at the given level of statistical significance. An analysis of the relationships indicates that Δ G E(CH 2) and ΔI are equivalent criteria of polarity for liquid stationary phases and that polarity can adequately be characterized by a single criterion.

Comments on column characterization: A sulfur column

The McReynolds' constants for liquid sulfur as a stationary phase in gas-liquid chromatography (GLC) are presented. A simple graphical method of pattern analysis is used to indicate the uniqueness of the sulfur column as compared with other stationary liquid phases characterized by McReynolds. The limitations of using a single factor (as polarity) for the basis for the selection of GLC columns is discussed.

Liquid crystals : II. Applications of liquid crystals as stationary phases in gas-liquid chromatography.

Liquid crystals : II. Applications of liquid crystals as stationary phases in gas-liquid chromatography.

Effect of temperature on the structural rearrangements of polyesters (LAC-series) when used as liquid stationary phases in gas-liquid chromatography

This study deals with the effect of temperature on the gas-chromatographic behaviour of thiols, alkanes, branched-chain alkanes and cyclic alkanes on polyester (LAC-446, LAC-745, LAC-772, LAC-860, LAC-886, LAC-841 and LAC-935) liquid stationary phases. Increases were observed in specific retention volumes as well as improvements in the separations at certain temperatures. The critical temperatures were different for the various liquid stationary phases; these were 110 °C for LAC-446 and LAC-886 and 120 °C for LAC-860 and LAC-772. Differential-thermal analysis of two of the liquid stationary phases indicated a change in the physical properties of the polymers during heating.

Liquid crystals : I. Synthesis and application as stationary phases in gas-liquid chromatography

2-R 1-4′-R-4-(4- n-alkoxybenzoyloxy)azobenzenes, where R = n-butyl, methyl and methoxy, R 1 = H and methyl and n-alkoxy = methoxy, ethoxy and n-butoxy were synthesized. They have long liquid crystalline “nematic” ranges and were used as stationary phases for the separation of positional isomers of di- and trisubstituted benzene. It was observed that lateral substitution (R 1) on the middle ring has a profound influence on the relative retentions of these compounds. The separation of mixtures of free phenolic isomers such as m- and p-cresols was difficult, whereas the separation of α- and β-naphthols could be easily achieved. Similarly, the separation of mixtures of free bases such as toluidines or picolines was difficult, but naphtylamines were separated with great ease. Also, the complete separation of all positional isomers of monochlorobiphenyl was achieved by using these liquid crystalline substrates.

Crosslinked polymethylphenylsiloxanes as adsorbents for gas chromatography

Crosslinked polymethylphenylsiloxanes that are suitable as adsorbents for gas-solid chromatography have been prepared. These new materials are characterized and evaluated as chromatographic supports. Their chromatographic properties are compared to OV-17, a linear polymethylphenylsiloxane, often used as a liquid phase in gas-liquid chromatography. Scanning electron micrographs show that the materials resemble agglomerates of tiny spheres. The materials have surface areas around 5 m 2/g and are thermally stable up to 350°. Small, polar compounds are eluted very early in columns prepared with these adsorbents in a manner similar to macroporous polymers like the Porapaks. Separations of chlorinated benzenes and phenols at temperatures up to 270° are shown.

Application of conventional thermodynamic approximations to mixed-solvent gas—liquid chromatography

Conventional thermodynamic approximations indicate a general non-linear dependence of partition coefficient on stationary-phase composition in mixed-solvent gas—liquid chromatography (GLC). The deviations from linearity have been calulated for varying circumstances, and the fact that many reported experimental measurements appear to conform to an approximately linear relation is explained by an extrapolation of solubility-parameter theory. The same thermodynamic treatment has been used to predict the behaviour of partially miscible stationary phases in GLC.

Mixed Preferred Stationary Phases in Gas-Liquid Chromatography

Mixed Preferred Stationary Phases in Gas-Liquid Chromatography

Studies of the Effects of Volatile Components from Gas Chromatographic Liquid Phases on Plasma Chromatographic Performance

Studies of the Effects of Volatile Components from Gas Chromatographic Liquid Phases on Plasma Chromatographic Performance

Polarity of polyester stationary phases

Sets of polyester condensates have been compared as stationary phases in gas-liquid chromatography by determination of their polarity constants both from the Rohrschneider probes at low temperature and usign a set of aromatic probes at high temperature. It was found that isomeric polyesters do not have the same polarities and, from the concept of methylene transfer between the diol and acid backbones of the polymers, a general conclusion is reached that transfer of methylene groups from the diol to the acid backbone increases the polarity of the phase. The lower (more polar) members of the series, however, displayed anomalous behaviour. An examination of poly(methyl methacrylate) as possible high-temperature polyester phase was carried out. This addition polymer displayed a lower polarity than its isomeric polycondensates and, although stable to a working temperature of 280°, the material proved unsatisfactory in performance—low column efficiencies were observed as a result of the high viscosity of the material.

Identification of the individual polychlorinated biphenyls in a mixture of gas—liquid chromatography

Retention indices were computed for all of the 210 possible chlorinated biphenyls on 13 gas chromatographic liquid phases. All possible pairwise comparisons of retention indices were made for each liquid phase, each pair of liquid phases and each set of three liquid phases. On the basis of a closeness criterion of 10 (Δ RI = Ri a — RI b = 10), those combinations of three or fewer phases which could distinguish between nearly all possible pairs of chlorinated biphenyls were selected. Further considerations such as column efficiencies, analysis time required, resolution achievable and availability led to the selection of several common liquid phases for the qualitative and, in some cases, quantitative analysis of the individual components of mixtures of polychlorinated biphenyls. A few specific applications are discussed.

Hydrocarbon stationary phases for gas-liquid chromatography

For the use of squalane as a standard stationary phase in gas-liquid chromatography, a preliminary clean-up step is suggested where the squalane, in a paraffin solvent, is passed successively through columns of activated carbon and alumina. A new standard non-polar stationary phase, produced by the catalytic hydrogenation of an Apiezon grease, is described. It has the advantage over squalane of a maximum operating temperature of 200°, allowing column polarities at high temperature to be evaluated.

Minimal spanning tree clustering of gas chromatographic liquid phases

Abstract A minimal spanning tree clustering algorithm is applied to gas chromatographic liquid phases. The tree is broken according to a rule which depends upon nearest neighbor information. The resulting minimal spanning tree divides the liquid phases into 13 clusters which vary in size from seven to 27 phases. Forty-one phases are designated as outliers in this analysis.

Feasibility of a one-dimensional search system

Abstract There has been frequent interest in the chemical literature in describing methods for the rapid search of large data collections. Since these collections may contain 10 4 –10 5 entries, any similarity search is difficult. However if one number is assigned to each entry and that number retains all similarity information, then a simple binary search can produce the data collection entries that are most similar to an unknown. This approach is investigated for a file of gas chromatographic liquid phases and for a large set of mass spectra. Obvious limitations occur when the data are multi-dimensional. However indications of multi-dimensional similarity are retained even in the difficult mass spectral example.

Determination of the loss of stationary phase in gas-liquid chromatography from the change in retention volume

The effects of liquid-phase bleeding on the determination of gas chromatographic quantities are important, especially when using a high-precision gas chromatograph. Equations are developed in which changes in solute retention volume are used to correct for losses of stationary phase. The method gives the best precision when frequent measurements are made of solute retention volume and of the corresponding total volume of carrier gas that has passed through the column, and is therefore most suited to chromatographs coupled to an on-line computer. It has been found that the change in solute retention volume with accumulated carrier gas flow is constant with n-octadecane and 3,3′-oxydipropionitrile as stationary phases; no influence of flow-rate has been observed in the range 25–85 ml/min. Pressures of octadecane at 333 and 371 °K, and of 3,3′-oxydipropionitrile at 373 °K, have been calculated from the bleeding. The values obtained agree well with literature values for the saturated vapour pressure. Thus, in many cases, the change in volume of the stationary phase with accumulated flow can be calculated from the saturation vapour pressure.

Solute retention on monofunctional gas chromatographic liquid phases of similar chain length

Solute retention on monofunctional gas chromatographic liquid phases of similar chain length

General contribution to the theory of retention index systems in gas-liquid chromatography : IV. Pre-calculation of interaction factors on mixed stationary phases in gas-liquid chromatography by computer

In earlier work, it was shown that gas chromatographic interactions can be characterized not only by the differences in retention indices, but also by quotients of the indices. This paper shows the practical application of Rohrschneider's concept based on quotients with the help of the McReynolds system for mixed stationary phases. Examples are given of the pre-calculation of retention indices on mixed stationary phases.

The properties of column packings containing small amounts of stationary phase in gas-liquid chromatography

Graphs are presented of the relations between the net retention volume per gram of column packing, V Ng, and the percentage of loading of Polsorb C with the stationary phases n-octadecanol and n-octadecane. From these relations and the value of the contact angle between the surface of diatomite and solutions of the stationary phases, it is shown that mono- and bimolecular layers of the stationary phase are formed on the support surface. The distribution of the stationary phases on the surface of the support is discussed in terms of the energetics of the support surface.