Mass spectrometrlc tracer pulse chromatography was used to determine the adsorption Isotherms of benzene on a graphltlzed carbon black adsorbent at temperatures from 10 to 60 °C. Concurrently, the retention volumes of Infinite dilution samples of n -pentane, n-hexane, acetone, and 2-butanone were measured as a function of surface coverage of the adsorbent with benzene. The retention volume data Indicated that both cooperatlvlty and Interference effects controlled the adsorption and retention of molecular probes. The data at temperatures above 20 °C agreed with a retention volume equation previously derived from the two-dimensional scaled particle adsorption model. The data Interpretation yielded values for the Interaction energy between like or unlike species adsorbed In a two-dimensional condensed "phase". These values were In the range of 2.5 to 3.0 kcal/mol for pentane-, hexane-, and butanone-benzene Interactions, slightly lower, 1.5-2.0 kcal/mol, for acetone-benzene, and approximately 1 kcal/mol for benzene-benzene Interactions. Surface coverage programming was demonstrated to significantly reduce the retention times and Improve the peak shapes for a series of model solutes on GCB. The Investigation showed that chromatographic methods with diverse types of molecular probes can be used to Isolate and quantify the relatively weak, but Important, Interactions between adsorbates In a two-dimensional adsorbed phase.Gas-solid chromatography, GSC, is a well-established separation technique which has been especially useful for the analysis of mixtures of light gases. Yet the method is not as popular as many other chromatographic methods. The primary difficulties encountered in the practical application of GSC are (i) excessively long retention times, (ii) asymmetric elution peaks, and (iii) low chromatographic efficiency.Temperature and flow programming are established methods for diminishing the retention time and peak width of normally late-eluting solutes. Temperature programming is far more commonly used than flow programming in spite of the seeming advantages of flow programming, viz., low temperature, high speed, and simplicity. Unfortunately, there are several critical limitations of this procedure for GSC. The primary difficulty is the limited range of accessible flow rates. With inert carrier gases, the retention volume of any solute
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.