Time filter

Source Type

Austin, TX, United States

Weatherly C.A.,University of Texas at Arlington | Zhang Y.,University of Texas at Arlington | Smuts J.P.,Vuv Analytics | Fan H.,University of Texas at Arlington | And 3 more authors.
Journal of Agricultural and Food Chemistry | Year: 2016

Four ionic liquid (IL) columns, SLB-IL59, SLB-IL60, SLB-IL65, and SLB-IL111, were evaluated for more rapid analysis or improved resolution of long-chain methyl and ethyl esters of omega-3, omega-6, and additional positional isomeric and stereoisomeric blends of fatty acids found in fish oil, flaxseed oil, and potentially more complicated compositions. The three structurally distinct IL columns provided shorter retention times and more symmetric peak shapes for the fatty acid methyl or ethyl esters than a conventional polyethylene glycol column (PEG), resolving cis- and trans-fatty acid isomers that coeluted on the PEG column. The potential for improved resolution of fatty acid esters is important for complex food and supplement applications, where different forms of fatty acid can be incorporated. Vacuum ultraviolet detection contributed to further resolution for intricate mixtures containing cis- and trans-isomers, as exemplified in a fatty acid blend of shorter chain C18:1 esters with longer chain polyunsaturated fatty acid (PUFA) esters. © 2016 American Chemical Society. Source

Groger T.,Helmholtz Center Munich | Groger T.,University of Rostock | Gruber B.,Helmholtz Center Munich | Gruber B.,University of Rostock | And 7 more authors.
Analytical Chemistry | Year: 2016

Fast and selective detectors are very interesting for comprehensive two-dimensional gas chromatography (GC × GC). This is particularly true if the detector system can provide additional spectroscopic information on the compound structure and/or functionality. Other than mass spectrometry (MS), only optical spectroscopic detectors are able to provide selective spectral information. However, until present the application of optical spectroscopy technologies as universal detectors for GC × GC has been restricted mainly due to physical limitations such as insufficient acquisition speed or high detection limits. A recently developed simultaneous-detection spectrometer working in the vacuum ultraviolet (VUV) region of 125-240 nm overcomes these limitations and meets all the criteria of a universal detector for GC × GC. Peak shape and chromatographic resolution is preserved and unique spectral information, complementary to mass spectrometry data, is gained. The power of this detector is quickly recognized as it has the ability to discriminate between isomeric compounds or difficult to separate structurally related isobaric species; thus, it provides additional selectivity. A further promising feature of this detector is the data analysis concept of spectral filtering, which is accomplished by targeting special electronic transitions that allows for a fast screening of GC × GC chromatograms for designated compound classes. (Figure Presented). © 2016 American Chemical Society. Source

Weber B.M.,University of Alberta | Walsh P.,Vuv Analytics | Harynuk J.J.,University of Alberta
Analytical Chemistry | Year: 2016

A GC-vacuum ultraviolet (UV) method to perform group-type separations of diesel range fuels was developed. The method relies on an ionic liquid column to separate diesel samples into saturates, mono-, di-, and polyaromatics by gas chromatography, with selective detection via vacuum UV absorption spectroscopy. Vacuum UV detection was necessary to solve a coelution between saturates and monoaromatics. The method was used to measure group-type composition of 10 oilsands-derived Synfuel light diesel samples, 3 Syncrude light gas oils, and 1 quality control sample. The gas chromatography (GC)-vacuum UV results for the Synfuel samples were similar (absolute % error of 0.8) to historical results from the supercritical fluid chromatography (SFC) analysis. For the light gas oils, discrepancies were noted between SFC results and GC-vacuum UV results; however, these samples are known to be challenging to quantify by SFC-flame ionization detector (FID) due to incomplete resolution between the saturate/monoaromatic and/or monoaromatic/diaromatic group types when applied to samples heavier than diesel (i.e., having a larger fraction of higher molecular weight species). The quality control sample also performed well when comparing both methods (absolute % error of 0.2) and the results agreed within error for saturates, mono- and polyaromatics. © 2016 American Chemical Society. Source

Vuv Analytics | Entity website

Knowledge Base Access Fill out the form to access the VUV Analytics Knowledge Base Recent Content: Determination of Hydrocarbon Group-Type of Diesel Fuels by Gas Chromatography with Vacuum Ultraviolet Detection - ACS A GC-vacuum ultraviolet (UV) method to perform group-type separations of diesel range fuels was developed. A Vacuum Ultraviolet Absorption Array Spectrometer as a Selective Detector for Comprehensive Two-Dimensional Gas Chromatography: Concept and First Results - ACS A recently developed simultaneous-detection spectrometer working in the vacuum ultraviolet (VUV) region of 125240 nm overcomes these limitations and meets all the criteria of a universal detector for GC GC GC-VUV Spectroscopy For Analysis of Fatty Acid Methyl Esthers Journal of Chromatography A VUV absorption spectra of 37 FAMEs, including saturated, monounsaturated, and polyunsaturated types were recorded ...

Vuv Analytics | Entity website

Posted: February 23, 2016 VUV Analyze engine reduces complexity and improves efficiency of routine fuel analysis Read More Posted: February 16, 2016 Dr. Nathan Dalleska will be exploring new applications using the VGA-100 Gas Chromatography Detector Read More Posted: December 16, 2015 VGA-100 gas chromatography detector announced as winner in the Analytical/Test category Read More Posted: October 28, 2015 Dr ...

Discover hidden collaborations