Modeling of Length Tunable Selectivity for Gas Chromatography PDF Download

Author: Lakshman Caldera
Publisher:
ISBN:
Category : Gas chromoatography
Languages : en
Pages : 98

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Author: Heather Lynne Smith
Publisher:
ISBN:
Category :
Languages : en
Pages : 324

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Author: Michael L. Akard
Publisher:
ISBN:
Category :
Languages : en
Pages : 398

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Book Description

Author: Robert L. Grob, PhD
Publisher: John Wiley & Sons
ISBN: 047165115X
Category : Science
Languages : en
Pages : 1059

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Book Description
The bible of gas chromatography-offering everything the professional and the novice need to know about running, maintaining, and interpreting the results from GC Analytical chemists, technicians, and scientists in allied disciplines have come to regard Modern Practice of Gas Chomatography as the standard reference in gas chromatography. In addition to serving as an invaluable reference for the experienced practitioner, this bestselling work provides the beginner with a solid understanding of gas chromatographic theory and basic techniques. This new Fourth Edition incorporates the most recent developments in the field, including entirely new chapters on gas chromatography/mass spectrometry (GC/MS); optimization of separations and computer assistance; high speed or fast gas chromatography; mobile phase requirements: gas system requirements and sample preparation techniques; qualitative and quantitative analysis by GC; updated information on detectors; validation and QA/QC of chromatographic methods; and useful hints for good gas chromatography. As in previous editions, contributing authors have been chosen for their expertise and active participation in their respective areas. Modern Practice of Gas Chromatography, Fourth Edition presents a well-rounded and comprehensive overview of the current state of this important technology, providing a practical reference that will greatly appeal to both experienced chomatographers and novices.

Author: Carrie Ann Leonard Coutant
Publisher:
ISBN:
Category :
Languages : en
Pages : 366

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Author: Roman Jaramillo
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Comprehensive two-dimensional gas chromatography (GCxGC) has emerged as a powerful analytical technique. Coupling two chromatographic columns greatly expands the number of compounds which can be detected, allowing for a more robust characterization of complex solutions, such as petrochemical samples and environmental waters. Through thermodynamic modeling of analyte retention times, GC method parameters, i.e., column dimensions, temperature program, etc., can rapidly be altered and evaluated without performing physical experiments. Chromatographers can determine the conditions which optimize the GC separation, producing shorter method runtimes while maintaining analyte resolution. Thermodynamic modeling is well understood in one-dimensional GC separations. However, significant second dimension modeling errors have consistently been observed when modeling GCxGC separations. A deeper understanding of the GCxGC separations process is required. A GCxGC modeling script was written which accounts for the various thermal zones present in a thermally modulated GCxGC system, a feature which past modeling scripts have consistently simplified, introducing sources of modeling errors. The modeling script can also model several GCxGC parameters which past modeling scripts have omitted, despite being frequently used by chromatographers, most notably the constant flow setting. Additionally, the modeling script is available for use in a web based graphical user interface, making it more accessible to chromatographers who don't have coding backgrounds. The GCxGC modeling script accuracy was evaluated using several hydrocarbon standards typically used in petrochemical applications. Modeling evaluations were performed on three LECO GCxGC systems. On two systems minimal retention time modeling errors were observed. On the third system, increased modeling errors were initially observed. However, the modeling script was modified to characterize and account for the unique separation mechanisms of the instrument, resulting in a third instance of accurate retention time modeling. The utility of the GCxGC modeling script was expanded by determining the thermodynamic indices of 50 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) on two GC columns, allowing for their retention time modeling. The modeling script was used to develop and optimize a GCxGC separation of PCDD/Fs in fish tissue matrix. Successful modeling of PCDD/F congener elution orders and patterns was achieved, demonstrating the thermodynamic indices' use as a congener identification mechanism. Finally, GCxGC modeling was applied to model alkane isovolatility curves, providing a method for performing second-dimension Kovats retention indices analyte identification. This technique provides a secondary analyte identification mechanism to supplement a mass spectral library search, supporting proper solution qualification. Thermodynamically modeling the isovolatility curves removes the prohibitive GCxGC instrument and method modifications which similar techniques require.

Author: Tingyue Gu
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 154

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Book Description
Liquid chromatography has proved to be one of the most important tools for separations. Rapid development in biotechnology has increased the demand for chromatography in analytical, preparative and large scale applications. The understanding of the dynamics of chromatography is imperative for the scale-up. This book is a systematic treatment of the general rate models for various forms of liquid chromatography including adsorption, size exclusion, affinity, reversed phase, hydrophobic interaction, and radial flow chromatography. Thermodynamic and mass transfer effects in liquid chromatography are discussed. Applications of computer programs for the rate models are described and the procedures for the scale-up of preparative- and large-scale liquid chromatography using the general rate models are given.

Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 692

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Author: Andrew James Grall
Publisher:
ISBN:
Category :
Languages : en
Pages : 312

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Author: Gordon Randall Lambertus
Publisher:
ISBN:
Category :
Languages : en
Pages : 514

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Book Description