May 13th 2024
In this edition of The LCGC Blog, Katelynn Perrault and James Harynuk discuss the technological needs one faces when setting up a workstation for chromatography data analysis.
Split Injection GC: Setting the Split Ratio in Shoot-and-Dilute GC
April 20th 2016Jack Cochran’s new column “Practical GC” provides readers with practical advice and new experimental evidence for how to get the best results from their gas chromatography (GC) systems. This instalment looks at understanding and using split ratio for “shoot and dilute” GC.
Chromatographers Get Into Cannabis
March 21st 2016Gas chromatography (GC) is an established and well-understood technique. As the cannabis industry grows, demand for analytical robustness is increasing for analytes such as pesticides, residual solvents, and terpenes. GC and GC coupled to mass spectrometry (GC–MS) are effective tools to address the demands of laboratories, growers, manufacturers, and consumers. This article provides an overview of the types of compounds that can be analyzed by GC, reviews the strengths and weaknesses of the analytical methods, and discusses areas of opportunity for chromatography.
Improving Aroma Profiling of Hops by Headspace TD–GC–TOF-MS
March 17th 2016This article describes the use of a headspace thermal desorption–gas chromatography–time-of-flight mass spectrometry (headspace TD–GC–TOF-MS) method to analyze complex aroma profiles from hops, and highlights how it can provide a rapid yet robust approach when comparing similar samples. The article also examines the potential of “soft” electron ionization at 12 eV for distinguishing between structurally similar monoterpenoids and sesquiterpenoids to provide better characterization of the often subtle differences in headspace profiles between different hop varieties.
Split Injection GC: Inlet Liner Choice for Shoot and Dilute GC
February 18th 2016Jack Cochran’s new column “Practical GC” provides readers with practical advice and new experimental evidence for how to get the best results from their gas chromatography (GC) systems. The next instalment looks at GC inlet liner choice for “shoot and dilute” GC.
Split Injection GC: The Benefits of “Shoot-and-Dilute” GC
November 9th 2015Jack 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.
What Is “Dead” Volume and Why Should Chromatographers Worry About It?
November 1st 2015The 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.
Split-Vent Traps: GC's Dirty Secret
October 1st 2015In 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..
Combining Thermal Desorption GC and TOF-MS for the Determination of Melon VOC Profiles
October 1st 2015A 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.
Developments in Gas Chromatography Using Ionic Liquid Stationary Phases
August 1st 2015Ionic 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.
Flame Ionization: GC's Workhorse Detector
July 1st 2015As 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.
Separating and Identifying Trace-Level Chemicals in Wine by Headspace SPME with GC×GC–TOF MS
May 6th 2015Solid-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.
Understanding Electron Ionization Processes for GC–MS
April 1st 2015Many 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.