Gas Chromatography (GC)

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.

The 36th International Symposium on Microscale Separations and Bioanalysis (MSB2020) will take place at the Conference Center Le Grand Large in the city of Saint‑Malo, France, from 5–8 April 2020.

The 44th International Symposium On Capillary Chromatography (ISCC) and 17th GC×GC Symposium will be held at the Palazzo dei Congressi, in Riva del Garda, Italy, from 24–29 May 2020.

Organosulphur compounds are important substances in the food industry because they can contribute to the flavour impression of a product. The human olfactory system’s sensitivity to sulphur leads to low flavour threshold values, making the analysis of these substances a challenging task. Gas chromatography (GC) with sulphur chemiluminescence detection (SCD) is a highly sensitive and selective technique for the analysis of sulphur compounds in various matrices. Using a range of different beers as an example, an approach is presented to reliably qualify and quantify sulphur components in beverages using headspace sampling and GC–SCD.

After 32 years as a columnist, John Hinshaw writes his final “GC Connections” article, examining how GC has changed over the years and considering where it might go in the future.

Multidimensional chromatography combining HPLC and GC, or LC–GC, sounds simple, but several factors complicate this combination, including solvent compatibility, separation time, and sample concentration.

An essential tool for troubleshooting and tuning GC–MS instruments is the tune report; this article explains the meaning and uses of this report when combined with a tuning compound.

Although manufacturers ship gas chromatographs with a collection of consumable parts and accessories, a number of other essential items should be on hand in every GC laboratory. What items are needed and how can they be used most effectively?

Pascal Cardinael and Valérie Agasse from the University of Rouen, in Mont‑Saint-Aignan, France, reveal the rationale behind miniaturization and the latest developments in miniaturized gas chromatography (GC).

Temperature programming is used in most capillary GC separations, but many analysts lack a good understanding of the principles behind this approach.

Our annual review of new developments in the field of gas chromatography, as seen at Pittcon and other venues

Chemical fingerprinting can provide evidence for quality differences resulting from botanical and geographical origins of primary food ingredients, post-harvest practices, production processes (such as traditional versus industrial processes), and the shelf-life evolution of finished products. This article discusses the strategic role and potential of comprehensive two-dimensional gas chromatography (GC×GC) combined with time-of-flight mass spectrometry (TOF-MS) and pattern recognition using template matching for data processing to unravel the quality traits of high-quality food products. Practical examples dealing with high-quality cocoa and extra-virgin olive oil are described.

Chemical fingerprinting can provide evidence for quality differences resulting from botanical and geographical origins of primary food ingredients, post-harvest practices, production processes (such as traditional versus industrial processes), and the shelf-life evolution of finished products. This article discusses the strategic role and potential of comprehensive two-dimensional gas chromatography (GC×GC) combined with time-of-flight mass spectrometry (TOF-MS) and pattern recognition using template matching for data processing to unravel the quality traits of high-quality food products. Practical examples dealing with high-quality cocoa and extra-virgin olive oil are described.

Is gas chromatography a mature technology? LCGC Europe spoke to Ronda Gras about a range of GC projects she has been working on to extend the scope of the technique, including a multi-hyphenated approach combining three modes of detection, a miniaturized micromachined GC system, and a novel in situ method to detect carbon dioxide in various matrices by incorporating 3D-printing technology in a FID.

In this instalment of the LCGC Blog, solutions for carryover problem in gas chromatography (GC) are considered.

Splitless injections are sometimes necessary for trace analyses, where the analyst hopes to recover 100% of the analytes that are injected. Unfortunately, splitless injections can be challenging and using an imperfect method can lead to loss of analytes and poor peak shapes. The choice of inlet liner can have an impact on the data and one must consider the effects of geometry, packing, deactivation, and volume on introduction of analytes into the system. Other important inlet parameters to consider include inlet temperature, splitless hold time, and initial oven temperature.

Comprehensive two-dimensional gas chromatography (GC×GC) offers significant improvement for volatile chemical separation. Selecting suitable first (1D) and second dimension (2D) columns normally requires consideration of the chemical composition of a sample. Replacing one of these dimensions with a two-column ensemble (for example, 1D1 + 1D2 for the 1D column), provided with a pressure tuning makeup gas between them, varies the relative retentions of compounds before the modulation step according to the junction pressure. This makes it possible to alter the apparent polarity of the 1D ensemble, and this alters peak positions in the 2D GC×GC space. This article presents an account of studies that suggest this offers potential for improved operation for a GC×GC laboratory.

Ethylene glycol is a particularly difficult compound to analyze because it is not easily extracted from water. Many environmental samples originate from water runoff at airports, where ethylene glycol is used as a de‑icing agent for airplanes during winter months. Hydraulic fracturing is a technique where pressurized fluid and sand or other solids (proppant) are used in gas drilling to allow gas extraction. Glycols are a common ingredient in most hydraulic fracturing fluid and play a key role in preventing emulsifications and stabilizing the solutions. The direct aqueous injection of ethylene glycol is challenging because it can be difficult to attain reproducibility and good peak shape. The large expansion volume of water can cause backflash, carryover can cause inconsistent results, and excess water can extinguish the flame ionization detection (FID) flame. This article describes a robust approach to analyze glycols in aqueous samples, which reduces downtime and maintains sensitivity.

A snapshot of key trends and developments in the chromatography sector according to selected panellists from companies who exhibited at Analytica 2018.

Gas chromatography makes use of a wide variety of detection methods, which really shine when deployed properly. Here’s guidance for how to choose the right one for your analysis.

Five top tips for improving your gas chromatography (GC) methods.

This study describes the analysis of fragranced washing detergent and washing powder using probe-based headspace and immersive sorptive extraction, in conjunction with analysis by thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS). As well as discussing the differences between the two samples, the analyte ranges covered by headspace and immersive sampling are compared.

Evaluating the ability of gas chromatography–vacuum ultraviolet detection (GC–VUV) to distinguish and correctly identify various isomer and isotopologue forms of an analyte through the lens of spectral similarity.

Three main points summarize the best ways to be successful in gas chromatography (GC): Capillary GC is clean GC; practice, practice, practice; and be a student of GC.

HS-SPME-GC–MS is a valuable technique for identifying volatile organic compounds, additives, and degradation products in industrial rubber, car labeling reflection foil, and bone cement materials.