"GC Connections” keeps readers up to date on the latest in methods, techniques, technologies, and best practices for gas chromatography. Columnist Nicholas H. Snow is the founding endowed professor of the Department of Chemistry and Biochemistry at Seton Hall University. He is interested in the fundamentals and applications of separation science, especially gas chromatography, sampling, and sample preparation for chemical analysis. His research group is very active, with ongoing projects using GC, GC–MS, two-dimensional GC, and extraction methods including headspace, liquid–liquid extraction, and solid-phase microextraction.

Column: GC Connections

Columns

Articles

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.

Going Low: Understanding Limit of Detection in Gas Chromatography (GC)

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

New Gas Chromatography Products for 2020–2021

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.


Let’s Get Small: Powerful Gas Chromatography in Small Packages

By moving from GC–MS to GC–MS/MS, you can have both universal and selective detection along with low detection limits. Here’s how it works.

Flying High with Sensitivity and Selectivity: GC–MS to GC–MS/MS

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.

What Chromatograms Can Teach Us About Our Analytes

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

How Can We Run a Gas Chromatograph from Anywhere?

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.

From Detector to Decision: How Does the GC Instrument Generate Your 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. Here, we explain the various types of cold injection and why you should consider it in your next instrument purchase or upgrade.

Beat the Heat: Cold Injections in Gas Chromatography

Our annual review of new gas chromatography (GC) products introduced in the past 12 months.

New GC Products Released for 2019–2020

Successful GC analysis requires careful control of carrier gas. Here, we explain how to measure and control flow rate, use constant pressure vs. constant flow, and more.