Gas Chromatography (GC)

Separation science is an intriguing and challenging (yes, let’s admit it) interdisciplinary field. Many of our daily rituals depend on effective chemical separations.

A review of the history and fundamentals for determining and reporting limit of detection (LOD) for analytical instruments and methods. Includes a discussion of the International Union of Pure and Applied Chemistry (IUPAC) and propagation of errors methods used for calculating LOD, and explains the limitations of the IUPAC method in modern chromatography.

I’d like to concentrate on variables that can really impact our chromatography, but may be on hidden, supplementary, or advanced pages of our software, or may appear on the main software acquisitions menus, but are poorly understood or rarely altered. These variables are often not specifically referenced in laboratory methods documents or, if they do appear, are poorly understood.

Decomposing animal tissue releases volatile organic compounds (VOCs), of interest in forensic science. We describe the use of GC×GC–qMS/FID retrofitted with a reverse fill/flush (RFF) flow modulator for analyzing these VOCs in a tropical climate.

The limit of detection (LOD) of an analytical method may be defined as the smallest concentration of analyte that has a signal significantly greater than that of a blank sample signal. We explore the sources of experimental uncertainty and variability in LOD determinations.

Pyrolysis–gas chromatography–mass spectrometry has advantages for the analysis of environmental microplastic samples compared to other leading analytical methods, including spectroscopic techniques.

We present our annual review of new products in gas chromatography, introduced between spring 2020 and spring 2021.

With full laboratory capability now available in smaller systems, the possibilities for rethinking our use of gas chromatography (GC) both inside and outside the laboratory are (almost) endless.

A look at how the data system controls the functions of the instrument. The same fundamental electronic principles used to manually control gas chromatographs in the 1970s are still at the center of today’s modern electronically controlled systems.

Capillary GC has been miniaturized, while maintaining some performance aspects of full-size laboratory systems. The benefits and challenges involved with considering these newer, smaller gas chromatographs for typical analytical problems are discussed.

The question, which is often asked of our technical support and applications chemists, is one to which I often reply, in the words of John F Kennedy, "Ask not what your column can for you, ask what you can do for your column.” OK, JFK substituted “column” for “country” in his version of the quotation, but as you will see, it’s a very relevant premise!

The question, which is often asked of our technical support and applications chemists, is one to which I often reply, in the words of John F Kennedy, "Ask not what your column can for you, ask what you can do for your column.” OK, JFK substituted “column” for “country” in his version of the quotation, but as you will see, it’s a very relevant premise!

Many chromatographic methods are automatically performed by today’s data systems, yet trace their origins to early, simpler techniques. This piece discusses how our data systems both assist and hinder in obtaining maximum information from chromatograms.

For GC, how do data systems both assist and hinder us in obtaining maximum information from chromatograms? We explain how a chromatogram can provide a wealth of information about an individual analyte in a sample, about the sample itself, and about how well a GC instrument is performing.

Judicious initial choices of gas chromatography (GC) column dimensions, and even a change of column dimension during method development, can lead to significant improvements in resolution.

As we approach the holiday season, in what has a been the most challenging of years both inside and outside of the laboratory, I wanted to produce a more light-hearted yet inspiring review of 2020 within the Arch Sciences Group laboratories.

How can GC overcome the complexity of dioxin separation and analysis?

This instalment explores how the data system controls the functions of the GC instrument. Drawing on classical electronics and instrument designs, the article describes the evolution of instrument controls from knobs and gauges on the front panel of the instrument to computer control and current web-based systems.

Computers control all aspects of modern GC instrument operation, from temperature to valve actuation. We look under the hood to see how this works.

Capillary GC is renowned for being a ”high efficiency” technique, meaning that we typically see very narrow peaks within our chromatograms. This leads to the ability to separate many components in a reasonable amount of time, which is of course analytically advantageous.

In the present research, similar chromatography fingerprints were obtained using finely-tuned cryogenic-modulation (CM) and flow-modulation (FM) comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS) experimental conditions.

Using the flame ionization detector (FID) as an example, we explain how the detector in a GC system generates a signal and how it is processed into chromatograms, and explore modern aspects of storing and processing digital data.

In gas chromatography, heating the sample in the inlet can lead to sample losses and loss of quantitative reproducibility, but these problems can be avoided using cold sample introduction. This article describes various types of cold injection and how they can benefit the analyst.

Optimizing gas chromatography (GC) separations typically involves making some informed choices around stationary-phase chemistry and column temperature programs

There are many potential causes of reduced peak size in gas chromatography (GC), and an inexperienced GC user may not know where to begin the troubleshooting process. Here, we review potential causes for reduced peak size in GC systems.

We are frequently asked about issues with reduced peak size in gas chromatography (GC), and I’m guessing this is related to just how difficult this problem is to troubleshoot. There are so many potential causes that an inexperienced GC user may not know where to begin the troubleshooting process. Fear not. What follows is our logical guide to locating and fixing the issues with loss of sensitivity, and we’ve tried to cover as many of the instrument and application issues that we can think of.

The Zebron ZB-PAH-EU and ZB-PAH-SeleCT offer unparalleled performance of targeted selectivity for PAHs in food, environmental, electronics, and fuel industries.

In this application, we look at purgeable volatile organic compounds by GC–MS using Zebron™ ZB-624PLUS™ GC columns.

In this application, we look at residual solvents per USP 467 using Zebron™ ZB-624PLUS™ and ZB-WAXPLUS™ GC columns.

How to reduce FAME run times by up to 75% and improve the separation of cis/trans FAME isomers while remaining compatible with AOAC, AOCS, and IOC regulatory methods.