Gas Chromatography (GC)

Jack Cochran’s new column “Practical GC” aims to provide readers with practical advice and new experimental evidence for how to get the best results from their gas chromatography (GC) systems. The first article in a series on split injection GC focuses on the advantages of using “shoot-and-dilute” GC.

The term “dead” volume often comes up in chromatography discussions and literature. This month, GC Connections addresses the nature of this phenomenon, when it can become a problem that affects chromatographic results, and how to understand and take control of it.

The Essentials: Optimizing Sample Introduction for Headspace GC

In GC split injection systems as much as 99% or more of the injected sample never enters the column: It is released downstream of the inlet where it can encounter and possibly perturb precision gas control devices. The split vent trap acts to prevent or at least moderate such effects. This month's installment addresses the operation and maintenance of split-vent traps..  

A method based on thermal desorption with gas chromatography–time-of-flight mass spectrometry (GC–TOF-MS) can elucidate how key volatiles vary with the size of the melon pieces. Such analytical information is of value in efforts to improve the quality and safety of ready-to-eat foods.

Ionic liquids (ILs) have become recognized in gas chromatography (GC) as stable and highly polar stationary phases with a wide application range. Having customizable molecular structures, ILs also offer a particular tunability that provides additional selectivity, and therefore may improve separation for neighbouring analytes. This article presents specific properties of IL phase capillary GC columns, including polarity scale and inner surface morphologies of IL columns. Application of IL phases in achiral and chiral GC, and multidimensional GC, are highlighted.

As the flame ionization detector (FID) approaches its 60th anniversary in 2017, this installment examines the crucial role that it has played and continues to play for all types of gas chromatography. Without the FID, the early development of gas chromatography (GC) would have proceeded more slowly especially in the petroleum industry and related hydrocarbon application areas.

The author shares his insights into the principles and practice of implementing and improving upon the original method to quantitate cyanide at trace concentration levels in human blood matrices using automated cryogenic trapping isotope dilution static headspace gas chromatography–mass spectrometry (GC–MS).

Solid-phase microextraction (SPME) coupled with comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry (GC×GC–TOF-MS) can be used to detect trace-level fungicides and compounds responsible for undesirable attributes known as “organoleptic faults” in wine. Of particular interest is the analysis of trace-level fungicides, which are difficult to detect using conventional quadrupole GC–MS techniques without resorting to selected ion monitoring mode. 

Cigarette smoke is a highly complex matrix and presents analytical difficulties for the analyst performing compound identification by gas chromatography analysis coupled with mass spectrometric detection (GC–MS). The development of a novel trapping system and a modified GC–MS layout (using dual chromatographic columns and cryogenic focusing devices) has improved the chromatographic separation of volatile and semi-volatile compounds found in cigarette smoke. This improvement has led to the potential to identify compounds usually masked by the solvent peak. This approach has also reduced the amount of peak overlapping by increasing the chromatographic peak capacity with the use of two capillary columns chosen for their analytical specificity.

The main objective of this study was to evaluate the capabilities of gas chromatography (GC) with time-of-flight mass spectrometry (MS) for screening pesticides in fruits and vegetables using a purpose-built accurate-mass database.

Many of us use electron ionization (EI) in gas chromatography–mass spectrometry (GC–MS) without a good understanding of the technique and how we might manipulate the process to give more appropriate results or a better understanding of the analytes under investigation.

A guide to simple troubleshooting steps in gas chromatography (GC) with an emphasis on petrochemical analysis.

This article describes sampling methodology for thermal desorption–gas chromatography (TD–GC) that can extend the compatible analyte range of tests used to determine chemicals released from materials, as well as associated indoor air quality measurements.

The regulatory and practical issues that surround allergenic fragrance use within cosmetics and cleaning products are explored in this article.

The transit of peaks through a gas chromatography (GC) column depends strongly on the thermal profile they encounter on the way.

Choosing the correct column selectivity and dimensions is fundamental to successful gas chromatography method development.

A rapid, high-throughput analytical method was developed and evaluated for the simultaneous determination of pesticides and environmental contaminants in fish.

Some might consider gas chromatography (GC) a mature technique. However, several substantial advances in GC technology in the past few years have proven that there is still room for innovation.

A brief history of GC detectors is presented.

A new, single method to replace the two-method approach using EPA Methods TO-15 and TO-13A to analyze both volatile and semivolatile organic compounds in air

How to spot weaknesses in methods before problems occur

How to spot weaknesses in methods before problems occur

If you change your GC carrier gas to hydrogen or nitrogen, you will need to consider various aspects of how that change will affect your methods.

What you need to know about pressure regulators, gas filtration, and gas fittings - and when to retire your cylinders