September 27th 2024
Here is some of the most popular content posted on LCGC International this week.
September 26th 2024
The Past, Present, and Future of Multidimensional Gas Chromatography
November 1st 2017The concept of (heart-cutting) multidimensional gas chromatography (MDGC) was introduced shortly after the invention of gas chromatography (GC). In that first experiment, the term “two-stage” was used to define the multidimensional process in applications involving the heart‑cutting of four hydrocarbon fractions, ranging from C5 to C8. The latter were separated first on a nonpolar packed column, and then on a polar one. A rather complex combination of valves enabled two-dimensional (2D) analysis. The great potential of the approach became immediately evident.
A Guide to Modern Comprehensive Two-Dimensional Gas Chromatography
July 11th 2017This article provides a short overview of the theory and practice of the rapidly developing field of two‑dimensional gas chromatography (GC×GC). Included in the discussion are a summary of the detectors used, an assessment of the options available for modulating the first-column eluate, and some recent developments in methodologies for interpreting the results.
The Role of Surface Coverage and Orthogonality Metrics in Two-Dimensional Chromatography
July 1st 2017The enhanced separation power of two-dimensional (2D) chromatography has become accessible thanks to the commercialization of dedicated two-dimensional systems. However, with great separation power comes great system complexity. All two-dimensional systems require a means for collecting and transferring fractions of the first dimension to the second dimension typically via a loop-based interface in on-line methods. It is important to collect a sufficient number of fractions to prevent loss of the first dimension resolution; that is, the sampling rate must be sufficient to prevent undersampling. Another key parameter to consider is selectivity. By coupling two selectivities that have unrelated retention mechanisms we are able to exploit the different physiochemical characteristics of the sample we wish to separate. This is the concept behind the term orthogonality. By coupling orthogonal selectivities and reducing under‑sampling, our system should be able to achieve the theoretical maximum two-dimensional peak
36th International Symposium on Capillary Chromatography and 9th GCxGC Symposium
May 4th 2012The International Symposium on Capillary Chromatography (ISCC) has established its reputation as forum for microcolumn separation techniques and, over the years, the most important developments in capillary gas chromatography, microcolumn liquid chromatography and electromigration techniques have been presented in this symposium series.
Analysis of Multiple Classes of Cigarette Smoke Constituents by GCxGC-TOFMS
February 1st 2012GCxGC-TOFMS provided a comprehensive analysis of tobacco smoke. Individual smoke constituents across several target compound classes were extracted, chromatographically resolved, then identified and quantified with mass spectral detection.
Two Dimensional Liquid Chromatography: A Powerful Tool for The Characterization of Humic Substances
October 17th 2011Analysis of natural compounds is becoming increasingly important. One thriving area is the evaluation and application of environmental biopolymers, such as humic substances (HSs) in various applications, including medicine, industry, agriculture and environmental protection.