Reverse gas chromatography

Kaiser, R. Temperature gradient chromatography. 1. Reversions gas chromatography. Chromatographia 1, 199(1968). 

Oster, H. Reversions gas chromatography, measuring technique and application. Z. Anal. Chem. 247, 257 (1969). 

Kaiser, R. Reversions gas chromatography. A new method for micro analysis of traces of volatile substances. Naturwissenschaften 5 7, 295 (1970). 

The curing kinetics of system EPS-l/DDM was studied by a method of reverse gas chromatography (RGC) [29]. The basic parameter received from processing of the experimental data, was the constant of reaction rate k determined for an interval of conversion degrees a = 0.1-0.7 of the kinetical curve degree of conversion-time (a-t). For the determination of k the standard procedure was used the dependences, a, on the reaction time t, as lg[a/(l-a)]=/ (t) which have appeared linear were made. Then the value k (see Equation (10.4)) was determined from a slope of these linear diagrams. Ketones (metyl ethyl ketone, 1,4-dioxane, cyclohexanone) were chosen as the standard substances for the determination of retention time with argon as the gas-carrier. 

B.N. Stepanov, The Study of Epoxide ResinsCured by Azomatic Diamines by Reversed Gas Chromatography, Chemical Technological Institute, Moscow, Russia, 1976. [PhD Thesis]... 

I hc reverse gas chromatography method implies control over equilibrium and elimination of a number of instrumental and methodical distortions (eg. the dependence of sorption on the amount of polymer adsorbent, the nature of motionless support for polymer, etc.) (Nesterov and Lipatov, 1976 Tager et al., 1978). The method is capable of determining x at small amounts of LMWL (v2 1). 

In certain cases Ig could not be detected by reverse gas chromatography [170, 197, 200, 205] because linear retention diagrams were ob-... 

The authors of Ref [11] fulfilled estimation with the aid of reversed gas chromatography and obtained the following magnitudes of this parameter for PC, poly (methyl methacrylate) and polysulfone 0.70, 0.60 and 0.65, accordingly (Table 15.2). 

More surprisingly, HDPE + polyurethane was compatibilized by adding kaolin clay, as judged by reverse gas chromatography [74]. Adsorption of polymer on the clay surface favored the thermodynamics of compatibility. 

A.E. Nesterov, Ju. S. Lipatov. Obrashhennaja Gazovaja Khromatografija V Termodinamike Polimerov (The Reversed Gas Chromatography in Polymer Thermodynamics). Kiev Nauk. Dumka, 1976 (in Russian). 

Thermodynamic properties of oligomer blends formed by oligoalkyleneglycoles and oligoethyleneadipinates have been first investigated by Yu.S. Lipatov and A.E.Nesterov, who used the reverse gas chromatography method for this purpose [85-87]. The systems mentioned above are interested not only due to their practical importance [88], but because despite systems described above they have both upper and lower solubility temperature and can help to reveal some specific characteristics of mixing thermodynamics of oligomer systems. 

A computational method in combination with a suitable force field provides an advantage in contrast to the commonly used group-number systems [9,43] for calculating the solubility parameters according to Hildebrand [10] and Hansen [11]. Recent comparisons of simulated solubility parameters with solubility parameters measured using reverse gas chromatography and other experimental methods [44] proved the accurateness of the simulated values. 

Many forms of chromatography have been used to separate mixtures of quinoline and isoquinoline homologues. For example, alumina saturated with cobalt chloride, reversed-phase Hquid chromatography, and capillary gas chromatography (gc) with deactivated glass columns have all been employed (38,39). 

A reversal of the 5 4H) 5 2H) equilibrium was established by demonstrating the presence of 4-isopropyl-2-trifluoromethyl-5(2fl )-oxazolone as an intermediate in the reaction of A-TFA-l-valine with the methyl ester of L-valine [Eq. (35)] using gas chromatography. The resulting product is a mixture of 74% l,l- and 26% d,l-A-TFA dipeptide methyl ester (see Section II, B, 4). 

F. J. Senorans, J. Tabera and M. Herraiz, Rapid separation of free sterols in edible oils by on-line coupled reversed phase liquid chr omatography-gas chromatography , 7. Agric. Food. Chem. 44 3189-3192 (1996). 

E. C. Goosens, D. de Jong, G. J. de Jong and U. A. Th Brinkman, Reversed-phase liquid cliromatography coupled on-line with capillary gas chromatography. II. Use of a solvent vapor exit to ina ease introduction volumes and introduction rates into the gas cliromato-graplT, J. Microcolumn Sep 6 207-215 (1994). 

J. Ogorka, G. Schwinger, G. Bmat and V. Seidel, On-line coupled reversed-phase high-performance liquid cliromatography-gas chromatography-mass specti ometi y , A powerful tool for the identification of unknown impurities in pharmaceutical products , J. Chromatogr. 626 87-96 (1992). 

One of the first examples of the application of reverse-phase liquid chromatography-gas chromatography for this type of analysis was applied to atrazine (98). This method used a loop-type interface. The mobile phase was the most important parameter because retention in the LC column must be sufficient (there must be a high percentage of water), although a low percentage of water is only possible when the loop-type interface is used to transfer the LC fraction. The authors solved this problem by using methanol/water (60 40) with 5% 1-propanol and a precolumn. The experimental conditions employed are shown in Table 13.2. 

Other endgroups can indirectly be quantified by first hydrolyzing the polymer in diluted chloric acid solution and then determining the composition of the compound by HPFC, reverse-phase chromatography, or gas chromatography (GC).45 48... 

Senorans, R J., Reglero, G., and Herraiz, M., Use of a programmed temperature injector for on-line reversed-phase liquid chromatography-capillary gas chromatography, /. Chromatogr Sci, 33, 446, 1995. 

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