A Practical Guide to Gas Analysis by Gas Chromatography

John Swinley,Piet de Coning

• Publisher: Elsevier
• Year: 2019
• ISBN:
  9780128188897
• Topic: Sciences physiques
• Subtopic: Chimie analytique

A Practical Gas Analysis by Gas Chromatography provides a detailed overview of the most important aspects of gas analysis by gas chromatography (GC) for both the novice and expert. Authors John Swinley and Piet de Coning provide the necessary information on the selection of columns and components, thus allowing the reader to assemble custom gas analysis systems for specific needs. The book brings together a wide range of disparate literature on this technique that will fill a crucial gap for those who perform different types of research, including lab operators, separation scientists, graduate students and academic researchers.

This highly practical, up-to-date reference can be consulted in the lab to guide key decisions about proper setup, hardware and software selection, calibration, analysis, and more, allowing researchers to avoid the common pitfalls caused by incorrect infrastructure.

• Shows, in detail, how valve configurations work, allowing readers to understand the building blocks of extremely complex systems
• Presents the complete infrastructure for setting up a gas analysis laboratory in a single source
• Includes a full chapter on practical analytical systems for analyzing various gas mixtures

Chapter 1

Overview and theory

Abstract

The book begins with a historical overview of chromatography in general and significant developments in the various fields of chromatography. The question of why we use chromatography is discussed.

The second section deals with the fundamentals of separation science and introduces phase separation and this is discussed in terms of both plate theory and rate theory. The van Deemter equation is introduced and each term discussed with particular reference to practical aspects of optimising average linear velocity of the carrier gas. Feed volumes, symmetry, resolution and column overloading are all introduced.

The final section covers the units used as well as Boyles, Charles, Dalton and Avogadro's laws leading up to the ideal gas law. The importance of normalising gas analysis results to standard temperature and pressure is discussed.

Keywords

Gas chromatography (GC); GC history; Linear velocity; Volumetric flow; Stationary phase; Mobile phase; Retention time; Resolution; Selectivity; Plate theory; Rate theory; Van Deemter; Peak symmetry; Measurement units; Boyles law; Charles law; Dalton law; Avogadro's law; Ideal gas law

1. 1.1 Historical overview
   1. 1.1.1 Early days
   2. 1.1.2 Gas chromatography
   3. 1.1.3 Other forms of chromatography
   4. 1.1.4 Why use chromatography?

1. 1.2 Chromatography fundamentals
   1. 1.2.1 Chemical separation
   2. 1.2.2 The mobile phase
   3. 1.2.3 Linear velocity and volumetric flow
   4. 1.2.4 The stationary phase
   5. 1.2.5 Retention time and retention factor
   6. 1.2.6 Resolution
   7. 1.2.7 Selectivity, the alpha value
   8. 1.2.8 The plate theory
   9. 1.2.9 The rate theory
      1. 1.2.9.1 Longitudinal diffusion
      2. 1.2.9.2 Slow equilibration
      3. 1.2.9.3 Flow paths
      4. 1.2.9.4 The Van Deemter equation
   10. 1.2.10 Dead volumes and unswept volumes
       1. 1.2.10.1 Feed volume
       2. 1.2.10.2 Detector volume
   11. 1.2.11 Peak symmetry
   12. 1.2.12 Overloading
   13. 1.2.13 Active sites
   14. 1.2.14 Resolution revisited
2. 1.3 Gas laws
   1. 1.3.1 Measurement units
      1. 1.3.1.1 Units of pressure
      2. 1.3.1.2 Units of volume
      3. 1.3.1.3 Units of temperature
   2. 1.3.2 Pressure and Boyle's law
   3. 1.3.3 Temperature and Charles' law
   4. 1.3.4 Volume and Avogadro's law
   5. 1.3.5 Partial pressures and Dalton's law
   6. 1.3.6 The ideal gas law
   7. 1.3.7 Vapour pressure
   8. 1.3.8 Vapour pressure and partial pressure
   9. 1.3.9 Standard temperature and pressure (STP)
3. References
4. Further reading

This chapter has three sections all of which is covered extensively in various books, articles and on-line sites on the Internet. There are many excellent books on the history of chromatography and a few are listed as references to this chapter. Similarly, much more detail on the theory of chromatography and gas laws is available in textbooks as well as the Internet. Again we mention a few books but there are many more.

1.1. Historical overview

It is always prudent to look back at the beginning and the developments that led to what we have today. Although there is always much to learn from history, it falls outside the scope of this book. However a very brief and selective overview would probably be acceptable.

1.1.1. Early days

Probably the earliest separations resembling chromatography were performed by dye chemists who separated mixtures of dyes by dipping the ends of string, filter paper or cloth into the dye and allowing the dye to separate into bands as it moves up by capillary action. The principle of gas-solid adsorption was used as early as 1905 by W. Ramsey to separate gases on activated charcoal and can be seen as a forerunner of gas-solid chromatography [1]. It is, however, generally accepted that the first real chromatography was performed by the 30 year old Russian specialist in botany, biochemistry, and physiology, Mikhail Semenovich Tswett. He started experimenting with packing solid powders such as calcium carbonate into a vertical glass column, applying a small amount of plant pigments to the top and then washing it through the column with a solvent. This caused the compounds to separate into coloured bands and he gave the process the name chromatography, probably from the Greek words chroma and graphein meaning colour writing. Column chromatography is still practiced in much the same way today although colour is not used to detect the separated compounds. He presented a lecture entitled ‘On a New Category of Adsorption Phenomena and its Application in Biochemical Analysis’ at a meeting of the Warsaw Society of Natural Scientists on 21 March 1903. This is a special date in the history of chromatography as it is generally accepted as the birth date of a technique that would become the leading separation technique of the 20th century.

Following on the work of Tswett was the use of chromatography by Leroy Sheldon Palmer who used the technique to isolate pigments, mainly carotenoids, in dairy products and biological tissues. His PhD thesis was published in 1913 and he published a book in 1922 on the separation of carotenoids. In 1931 Richard Kuhn from Germany and his student Edgar Lederer, from France, used the same technique to separate biological molecules. It took another ten years for the next major development. While studying the amino acid composition of wool using counter current liquid-liquid separation two British chemists, Arche...