At least two independent parameters are necessary for compound identification in metabolomics. We have compiled 2 212 electron impact mass spectra and retention indices for quadrupole and time-of-flight gas chromatography/mass spectrometry (GC/MS) for over 1 000 primary metabolites below 550 Da, covering lipids, amino acids, fatty acids, amines, alcohols, sugars, amino-sugars, sugar alcohols, sugar acids, organic phosphates, hydroxyl acids, aromatics, purines, and sterols as methoximated and trimethylsilylated mass spectra under electron impact ionization. Compounds were selected from different metabolic pathway databases. The structural diversity of the libraries was found to be highly overlapping with metabolites represented in the BioMeta/KEGG pathway database using chemical fingerprints and calculations using Instant-JChem. In total, the FiehnLib libraries comprised 68% more compounds and twice as many spectra with higher spectral diversity than the public Golm Metabolite Database. A range of unique c...

/pdf/fiehnlib-mass-spectral-and-retention-index-libraries-for-1740ecxbfm.pdf

FiehnLib: Mass Spectral and Retention Index Libraries for Metabolomics Based on Quadrupole and Time-of-Flight Gas Chromatography/Mass Spectrometry

The many faces of packed column supercritical fluid chromatography--a critical review.

Effect-directed analysis supporting monitoring of aquatic environments - An in-depth overview

Supercritical fluids in separation science--the dreams, the reality and the future.

Analytical multidimensional gas chromatography (MDGC) and the excellent separation efficiency it achieves serve advanced characterization of complex volatile and semi-volatile samples, which is unlikely to be accomplished by single-dimensional chromatography. Here, we provide a technical overview of recent method implementation in MDGC, for both the classical sense (i.e. conventional heart-cut MDGC), including recent approaches to MDGC, and the comprehensive two-dimensional gas chromatography (GC × GC) variant. We summarize selected applications in diverse fields that best typify the role of these methods. We also draw attention to concepts (e.g., orthogonality of separation mechanisms and recently introduced microfluidic technology), and briefly comment on compatibility of detection systems. As a guide to potential opportunities for continued innovation in multidimensional applications, we highlight the capabilities of GC platforms that either combine various GC × GC and MDGC arrangements or offer alternative operational modes for implementation of these methods.

Multidimensional gas chromatography

Method translation in gas chromatography (GC) is a variation of components (columns, carrier gases, detectors, etc.) and parameters (pressures, temperature programs, etc.) of a method in a way that maintains the peak elution pattern. The concept is based on the fact that the void time can be viewed as a universal time unit in GC; method translation is the scaling of the time axis of the temperature program relative to the void time. Method translation can be used to reduce analysis time, improve resolution, and adopt a method to a different carrier gas or to a different outlet pressure (vacuum for mass spectrometers, ambient pressure for conventional detectors, etc.). It can also be used for retention time locking (RTL). Theoretical and practical aspects of method translation and RTL are analyzed. It is shown that a constant-pressure method can be translated between the columns that have the same stationary-phase type and phase ratio. Method translation also implies that optimum temperature ramp rate (exp...

Method Translation and Retention Time Locking in Partition GC

Interest in the development and implementation of fast gas chromatography (GC) methods continues to increase. Fast GC method development and validation can be simplified and more successful if a few key theoretical and practical concepts are kept in mind. Key concepts such as speed-optimized flow rate, optimal temperature-program rate, sample capacity, “cut the column”, and principles of method translation are discussed.

Theoretical and practical aspects of fast gas chromatography and method translation

Comparison of one-dimensional and comprehensive two-dimensional separations by gas chromatography

Evaluation of conditions of comprehensive two-dimensional gas chromatography that yield a near-theoretical maximum in peak capacity gain.

Several optimization criteria for column heating rate in temperature programmed gas chromatography (GC), under different optimization constraints are identified. Applying these criteria to experimental data, it is shown that when column pressure drop is high, the optimum heating rate for n-alkanes and pesticides in a column with a silicone stationary phase of a typical thickness is about 10°C per void time. This heating rate is recommended as a default for all temperature programs in capillary GC. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 508–514, 2000

Matthew S. Klee

Papers

Method Translation and Retention Time Locking in Partition GC

Theoretical and practical aspects of fast gas chromatography and method translation

Comparison of one-dimensional and comprehensive two-dimensional separations by gas chromatography

Evaluation of conditions of comprehensive two-dimensional gas chromatography that yield a near-theoretical maximum in peak capacity gain.

Optimal heating rate in gas chromatography