|Analysis of Terpenes Using Gas Chromatography with Vacuum Ultraviolet |
Changling Qiu, Jonathan Smuts, Phillip Walsh, and Kevin A. Schug
The VUV absorption spectra for different terpenes were distinctive and differentiable. GC-VUV demonstrated the capabilities for qualitative and quantitative analysis of terpenes in turpertine mixtures. Chromatographic coeluting signals can be deconvolved by the VUV data analysis software.
|Determination of C2-C12 Aldehydes in Water by SPME Arrow On-Fiber Derivatization and GC/MS|
Peter Egli, Beat Schilling, Guenter Boehm, Kai Schueler
A method applying SPME Arrow extraction and on-fiber derivatization for the quantitation of C2-C12 aldehydes in water by GC/MS is described.
|Assessing Diversity in Cassava through the Application of Metabolomics|
Margit Drapala, Elisabete Carvalhoa, Laura Perez-Fonsa, Elliott Pricea, L. Augusto Becerra Lopez-Lavalleb, Paul D. Frasera
In the present study metabolomic platforms have been established for Cassava and used to assess the biodiversity present in Cassava germplasm collections and elucidate underlying biochemical mechanisms associated with traits of interest.
|PredRet: Prediction of Retention Time by Direct Mapping between Multiple Chromatographic Systems|
Jan Stanstrup, Steffen Neumann, Urška Vrhovšek
Retention time (RT) information is under-utilized in LC-MS based metabolomics and sharing of RTs between systems is not currently possible. PredRet is a new system that allows highly accurate mapping and prediction of RTs between LC systems.
|Minimizing Carry-over for High Throughput Analysis|
Christian Berchtold1, Reto Bolliger2, Guenter Boehm2, Götz Schlotterbeck1
Minimal carry-over is a prerequisite for high throughput analysis. However, minimized carry-over and cycle time are competing and a careful optimization is mandatory. In this study the influence of wash conditions on carry-over of various compounds was investigated. A strategy to minimize carry-over was developed. The influences of different wash tasks were investigated. Finally the contribution of different system components such as injector valve or column was studied.
|A Comparison of ITEX Dynamic Headspace–GC/MS to other Enrichment Techniques for Analysis of Flavoring Compounds|
Douglas Doster1; Roger Pearson1; Sean Eppel1; Ken Rice1; Tom Flug2; Brian Peat2; Guenter Boehm2
Enrichment techniques are commonly used for the analysis of flavoring compounds in different matrices with GC/MS. Analysis of flavoring compounds is done by purge & trap, SPME or headspace, depending on requirements for sensitivity. The In-Tube Ex¬traction (ITEX) Dynamic Headspace uses a micro trap filled with an adsorbent material to efficiently extract the compounds. Here we evaluate if the ITEX can be used to effectively analyze for these compounds and reduce the analyst’s time involved.
|Optimization of a Vacuum Ultraviolet Photoionization source for Gas Chromatography used with a High Resolution Time of Flight Mass Spectrometer|
Lloyd Allen and Viatcheslav Artaev
-Tune solution allows optimization of ion source parameters for
both proton transfer and direct ionization
-Independent ionization processes exist for M+ and MH+
-Optimizing for dopant signal intensity yields inferior results
-Degree of fragmentation remains relatively constant over a
range of source conditions
|High Performance Comprehensive Two-Dimensional Gas Chromatography Coupled with a High Resolution Multi-Reflecting TOFMS for Confident Non-Target Analyte Identification|
Scott J. Pugh, Viatcheslav Artaev, Mark F. Merrick, Jack Cochran
The use of comprehensive two-dimensional gas chromatography to help increase chromatographic resolution is a major step in tackling the problem of confident peak identification in a complex sample matrix. Combining the separation power of two-dimensional gas chromatography, with resolving power greater than 25,000, and sub ppm mass accuracies of a high resolution multi-reflecting TOFMS is the ideal solution to confident compound identification within a complex sample matrix.
|Fragmentation Trees for Automated de novo Interpretation of Impure Electron Ionization Spectra from Gas Chromatographic Complex Mixture Analysis—Chemical Deconvolution|
Kevin Siek, Vasily Makarov, Viatcheslav Artaev, Dmitry Mazur, Albert T. Lebedev
-Chemical deconvolution algorithms accurately reported independent
components of dead coelutions where such components belong to distinct chemical classes.
-Present algorithms fail to distinguish chemically similar analytes such as branched and linear alkanes, thus chemical deconvolution is not a
substitute for GCxGC.
-Chemical deconvolution algorithms accurately rejected more than 80% of spurious signals from manually curated spectra found to be contaminated with unrelated signa
|Effective Comparison of Yeast Extracts Using High Resolution GC and GCxGC-HRTOFMS|
David E. Alonso and Joe Binkley
The Pegasus GC-HRT and GC-HRT 4D instruments are effective tools for the comprehensive analysis of yeast extracts.
• Enhanced chromatographic resolution of the HRT 4D system facilitated compound characterization by improving spectral similarity scores
• High quality data resulted in excellent spectral similarity scores when compared to large, well-established databases (NIST, Wiley)
• High resolution, accurate mass data was crucial for determination of fragment, molecular, and adduct
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