Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Group-Type Identification of Oil Samples Using Comprehensive Two- Dimensional Gas Chromatography Coupled to a Time-of-Flight Mass Spectrometer (GC×GC-TOF) (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 507-510 
    Details
    ISSN: 0935-6304
    Keywords: Comprehensive two-dimensional GC ; time-of-flight ; oil analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---In this work a comprehensive two-dimensional system (GC×GC) was coupled to a time-of-flight mass spectrometer (TOF/MS) for the analysis of oil samples. Group-types like the alkanes and saturated cyclic compounds (naphthenes), which are present in oil, are shown separately by selecting their unique masses. On selecting appropriate ion fragments, this method also permits the determination of sulfur- and oxygen-containing species in oil. Former results obtained by FID detection could be confirmed. After proper selection of unique ions in GC×GC-TOF both selectivity and sensitivity increase.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 2
    Electronic Resource
    Electronic Resource
    Comprehensive Two-Dimensional Gas Chromatography (GC×GC) as a Diagnostic Tool (1998)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 21 (1998), S. 63-64 
    Details
    ISSN: 0935-6304
    Keywords: Injection port performance ; comprehensive two-dimensional GC ; GC× ; GC ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 3
    Electronic Resource
    Electronic Resource
    Possibilities and Limitations of Fast Temperature Programming as a Route towards Fast GC (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 509-513 
    Details
    ISSN: 0935-6304
    Keywords: Fast GC ; fast temperature programming ; resistive heating techniques ; short columns ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---One possible way to speed up a gas chromatographic analysis is the application of fast temperature programming by using resistive heating techniques. With this heating technique programming rates up to 20° per second can be reached. A relative standard deviation of retention times better than 0.2% is obtained. Using fast temperature programming the analysis-times of a mineral oil sample, an industrial oligomer sample, and toxic compounds in diesel fuel have been reduced 5 to 20 times, compared to a standard temperature programmed analysis. In most cases resistive heating cannot be applied to reduce the analysis time of a complex sample. The use of fast temperature programming is preferable to the use of short columns and columns operated at above-optimum carrier gas velocities.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 4
    Electronic Resource
    Electronic Resource
    An on-line coupled HPLC-HRGC system for the quantitative characterization of oil fractions in the middle distillate range (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Microcolumn Separations 7 (1995), S. 345-354 
    Details
    ISSN: 1040-7685
    Keywords: HPLC-HRGC coupling ; on-column interface ; oil fractions ; middle distillates ; sulphur-containing compounds ; quantitative characterization ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A commercially available HPLC-HRGC instrument was adapted to enable the full quantitative characterization of oil fractions in the range 150-400°C. The HPLC separates the sample into five fractions: saturates, mono-aromatics, di-aromatics, fluorenes + dibenzothiophenes, and tri-aromatics. These fractions are subsequently quantitatively transferred via an on-column interface to the HRGC part of the system. This transfer is performed into an empty, wide-bore precolumn (retention gap), which enables a refocussing effect of the compounds of interest in the tail of the HPLC mobile phase, which acts as a solvent in the GC. A solvent vapor exit in the system enables the vent of the major part of this solvent. The final HRGC separation provides a carbon distribution of the saturates and the mono-aromatics and enables the identification of a number of compounds in the other three fractions. It is demonstrated that the described method is quantitative for the hydrocarbons, but also for sulphur-containing compounds in only those samples that have a low sulphur content. © 1995 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mcs.1220070407
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Compehensive two-dimensional gas chromatography (GC×GC) and its applicability to the characterization of complex (petrochemical) mixtures (1997)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 20 (1997), S. 539-544 
    Details
    ISSN: 0935-6304
    Keywords: Multi-dimensional gas chromatography ; Orthogonal separations ; GCxGC ; Comprehensive two-dimensational chromatography ; Characterization of petroleum samples ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In general, petrochemical products contain only a limited number of chemical classes of compounds (sample dimensionality). The enormous number of individual components within these classes, however, soon puts limitations upon a single chromatographic technique when it comes to adequate characterization of these products. Comprehensive two-dimensional gas chromatography (GC×GC) clearly opens the possibility of estimating the composition of hydrocarbon mixtures in a far more detailed fashion than hitherto possible. Although the emphasis of papers of GCxGC thus far almost exclusively applies to the unsurpassed peak-capacity, in the oil industry there is a need for characterization, rather than for analyzing all the individual compounds. In principle a GCxGC system can provide an almost perfect match between its intrinsic properties and the dimensionality of oil samples. To establish the applicability of GCxGC towards petrochemical analytical challenges, a commercially aavailable prototype instrument was subjected to an exhaustive characterization of a typical hydrocarbon precess stream and a fast characterization of a light gas oil. Although there are no fundamental limitations towards the quantitative aspects of a GCxGC system, this paper confines itself to qualitative results only. Quantitative aspects of GCxGC will be published in a forthcoming paper.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240201005
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Quantitative Aspects of Comprehensive Two-Dimensional Gas Chromatography (GC×GC) (1998)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 21 (1998), S. 47-54 
    Details
    ISSN: 0935-6304
    Keywords: multidimensional gas chromatography ; comprehensive two-dimensional gas chromatography ; GC×GC ; characterization of petroleum samples ; quantitative analyses ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A software program was developed to enable the quantification of the complex 3D-data sets as produced by GC×GC. Using this software, it was demonstrated that the detectability limit of GC×GC in our study is 18 times better than that of ‘normal’ capillary gas chromatography (CGC). This enhancement is due to the signal increase produced by the thermal modulation effect. The relative standard deviation of 0.9% as measured on a test mixture was excellent. Furthermore, a comparison was made for the group-type separation of heavy gas oils between the hyphenation of LC and GC (LC-GC) and GC×GC. Although these separations are different in nature, the agreement of the results of both methods was very good. The results of GC×GC may even be more accurate, since, different from CGC, even in the most complex chromatograms the baseline in the second dimension chromatograms is always present.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 7
    Electronic Resource
    Electronic Resource
    The characterization and quantitation of sulfur-containing compounds in (heavy) middle distillates by LC-GC-FID-SCD (1997)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 20 (1997), S. 131-137 
    Details
    ISSN: 0935-6304
    Keywords: LC-GC hyphenation ; Sulfur chemlluminescence detector ; Organo-sulfur compounds ; Hydrodesulfurizalion ; Middle distillates ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A modified sulfur chemiluniinescence detector (SCO) has been interfaced to a HPLC-HRGC hyphenated system. This combination enables the full characterization and quantitation of the sulfur containing compounds in (heavy) middle distillate oil fractions (boiling range 150-450°C). The system is suited to identify and determine the various groups of orgaiio-sulfur structures such as: thiols + sulfides + thiophencs, benzothiophenes, dibenzothiophenes and benzo-naphthothiophenes. Within these groups a separation according to boiling point is accomplished. Therefore it allows the separation, identification and quantitation of a number of individual species, especially those which are refractory to hydrodesulfu-rization (HDS), such as 3-methyl-benzothiophene, 4-methyl-dibenzothiophene and -J,6-dimethyl-dibenzothiophene. The analysis of these groups and specific compounds is the key in understanding the kinetics of the chemistry involved in HDS. The complete instrumental set-up is fully automated by computer control. To suppress possible interferences and quenching of the sulfur response of the SCL from (large amounts of) hydrocarbons, it is aligned above the adapted flame ionization detector (FID) of the GC. This renders a sensitivity of the SCO for sulfur of 2 pg. s-1, which corresponds to a minimum detectable level for individual sulfur species in oil fractions for the complete system of 1 ppm (mg. kg-1) sulfur. Its linear dynamic range exceeds 105, which means that also untreated, high sulfur containing feedstocks can be analyzed directly. The selectivity of sulfur to carbon of the modified SCO exceeds 106. A number of HDS feedstocks and desulfurized products of different desulfurization levels have been analyzed with the system. From the analysis results the behavior of the refractory compounds in HDS can now be followed closely.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240200303
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Proper Tuning of Comprehensive Two-Dimensional Gas Chromatography (GC×GC) to Optimize the Separation of Complex Oil Fractions (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 182-188 
    Details
    ISSN: 0935-6304
    Keywords: Comprehensive two-dimensional gas chromatography ; GC×GC ; thermal modulation ; oil analysis ; petroleum analysis ; analysis of middle-distillate oil fractions ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Comprehensive two-dimensional gas chromatography (GC×GC) is an utterly suitable separation technique for the analysis of complex samples, such as oil fractions. Once the two columns and the operating conditions are properly tuned, the technique is able to provide a detailed characterization of such materials. Some considerations applying to the tuning of a GC×GC system for a specific separation are presented and discussed. The authors present a number of different column sets and conditions which allow the separation of a non-aromatic hydrocarbon solvent, a kerosene, the light end of a crude oil, and an olefinic fraction, respectively. The highly structured GC×GC chromatograms, together with chemical knowledge about the samples, provide a much more comprehensive characterization of the samples than hitherto possible.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...