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Comprehensive two-dimensional GC

Although comprehensive two-dimensional gas chromatography has not been applied to any great extent in forensic analysis, the technique shows great promise when samples or sample matrices are complex. For example, when oil is spilled into waterways, assigning responsibility for the economic and environmental damage is often difficult. Gaines et al. employed comprehensive two-dimensional GC in the forensic analysis of samples collected at oil-spill sites and were able to obtain results which were comparable to those obtained by classical methods (39). This article also... [Pg.425]

Comprehensive two-dimensional GC has also been employed for the analysis of pesticides from serum, which, although not strictly a forensic analytical problem , provides an example of the promise of this technique to forensic applications, such as the analysis of drugs of abuse (40). Two-dimensional gas chromatograms of a 17-pesticide standard and an extract from human serum are shown in Figure 15.13. The total analysis time of about 5 min, high peak capacity and the separation of all... [Pg.426]

Figure 15.13 Comprehensive two-dimensional GC chromatogram of a supercritical fluid exti act of spiked human semm. Peak identification is as follows 1, dicamha 2, tiifluralin 3, dicliloran 4, phorate 5, pentachlorophenol 6, atrazine 7, fonofos 8, diazinon 9, cWorothalonil 10, terhufos 11, alachlor 12, matalaxyl 13, malathion 14, metalochlor 15, DCPA 16, captan 17, folpet 18, heptadecanoic acid. Adapted imm Analytical Chemistry, 66, Z. Liu et al., Comprehensive two-dimensional gas chromatography for the fast separation and determination of pesticides exuacted from human senim , pp. 3086-3092, copyright 1994, with pemiission from the American Chemical Society. Figure 15.13 Comprehensive two-dimensional GC chromatogram of a supercritical fluid exti act of spiked human semm. Peak identification is as follows 1, dicamha 2, tiifluralin 3, dicliloran 4, phorate 5, pentachlorophenol 6, atrazine 7, fonofos 8, diazinon 9, cWorothalonil 10, terhufos 11, alachlor 12, matalaxyl 13, malathion 14, metalochlor 15, DCPA 16, captan 17, folpet 18, heptadecanoic acid. Adapted imm Analytical Chemistry, 66, Z. Liu et al., Comprehensive two-dimensional gas chromatography for the fast separation and determination of pesticides exuacted from human senim , pp. 3086-3092, copyright 1994, with pemiission from the American Chemical Society.
Recently, multi-dimensional GC has been used for highly complex separations, especially in analysis of fuels, environmental samples and flavors. Most recently, comprehensive two-dimensional GC, in which samples are continuously taken form the effluent of the (long) first... [Pg.483]

Fig. 14.13. Chromatograms showing single and comprehensive two-dimensional GC of drugs extracted from urine. (A) GC-FID chromatogram, (B) Pulsed GcxGC chromatogram (C) GCxGC contour plot. Adapted with permission from Ref. [15, Fig. 14.3]. Complete details on separation conditions and analyte identity can be found in the original paper. Fig. 14.13. Chromatograms showing single and comprehensive two-dimensional GC of drugs extracted from urine. (A) GC-FID chromatogram, (B) Pulsed GcxGC chromatogram (C) GCxGC contour plot. Adapted with permission from Ref. [15, Fig. 14.3]. Complete details on separation conditions and analyte identity can be found in the original paper.
Comprehensive two-dimensional GC (GC x GC) has been applied to the analysis of many complicated systems including petroleum and air samples (Ryan and Marriott, 2003). This technique is more powerful than previously developed heart-cutting methods, in which a small section of eluent from one column is injected onto a second for further separation (Ryan and Marriott, 2003). In GC x GC, two columns with fundamentally different separation mechanisms are cormected by a modulator (O Figure 1-2). The modulator continuously refocuses portions of the eluent from the first column onto the second column. The... [Pg.4]

For the analysis of complex mixtures, modern coupling techniques such as GC-MS, GC-FTIR, HPLC-MS, CE-MS and comprehensive two-dimensional GC [832, 836-838a] are valuable and sometimes essential tools. [Pg.227]

MDGC, and comprehensive two-dimensional GC, or GCxGC), faster separation techniques (fast GG), fast methods for quality assessment or process control in the flavour area ( electronic noses and fingerprinting MS) and on-line time-resolved methods for analysis of volatile organic compounds (VOGs) such as proton-transfer reaction MS (PTR-MS) and resonance-enhanced multi-photon ionisation coupled with time-of-flight MS (REMPI-TOFMS). The scope of this contribution does not allow for lengthy discussions on all available techniques therefore, only a selection of developments will be described. [Pg.314]

Mondello, L., Casilli, A., Tranchida, P.Q., Dugo, R, Dugo, G. (2005) Comprehensive two-dimensional GC for the analysis of citrus essential oils. Flavour Fragrance J. 20 136-140. [Pg.353]

Finally, the development of fast GC [61-63] and comprehensive two-dimensional GC (GC X GC) [64-66] address the continuous demand for increased speed and separation power in routine analysis. The former technique allows a dramatic reduction in analysis time without sacrificing resolution, while the latter offers a markedly increased separation power without altering the analysis time. A fast GC method for the analysis of cocaine and other drugs of forensic relevance has been published by Williams et al. [67]. They used a GC instrument in which the column was resistively heated at rates of up to 30°/s which allowed separation of 19 compounds within 1.5 min. A GC x GC time-of-flight mass spectrometry (TOF-MS) method has been proposed by Song et al. [68] for the analysis of a mixture of 78 drugs of interest, including cocaine and benztropine. [Pg.349]

Comprehensive two-dimensional GC (GC X GC) was introduced in the early nineties by the late John Phillips. This technique differs from GC-GC in that the entire sample injected to the column is subjected to separation in both dimensions. In GC X GC, the sample injected into the system is first subjected to chromatographic separation in the first column (primary dimension), as... [Pg.170]

FIGURE 3.25 The concept of multidimensional GC (a) Single heart-cut GC analysis, in which a portion of the effluent from the primary column containing analytes of interest is diverted to the second dimension column and subjected to additional separation over an extended period of time, (b) Dual heart-cut GC analysis, in which two regions with coelutions are diverted to the second dimension column, with less time to perform each separation, (c) Comprehensive two dimensional GC analysis, in which the sizes of the sequential heart-cut fractions are very small, and the time to develop each sequential second dimension chromatogram is very short. [Pg.171]

If each separation mechanism applied to the resolution of a mixture is defined as a separation "dimension," the subsequent application of different separation mechanisms can be called a multidimensional approach. This chapter briefly introduces the concept of multidimensionality in the context of GC separations and discusses how switching from traditional multidimensional GC (MEXjC or GC-GC) to comprehensive two-dimensional GC (GCxGC) dramatically enhances the potential of the technique. [Pg.4]

Rgure 1 (A) Peak capacity (n expressed for a single GC column. (B) Peak capacity expressed for a multidimensional GC analysis, with a first-dimension GC column (n ) and one heartcut event to a second-dimension GC column capacity (rtic). Total capacity nt+rric. (C) Peak capacity expressed for a comprehensive two-dimensional GC analysis where each dimension has capacity and ntc, respectively. Total capacity nt x mt. [Pg.1839]

Figure 3 (A) Single-column GC analysis result. (B) Selected incompletely resolved heartcuts from A are directed to a second column where improved separation is achieved. Here two heart-cuts are performed. (C) Illustration of multidimensional analysis GC/MS, where the second dimension is a mass spectrum recorded at the mass spectral data acquisition rate. The success of this approach depends on the uniqueness of the mass spectrum at each point in the chromatogram. (D) The comprehensive two-dimensional GC method ideally spreads out the components in a two-dimensional space, according to the characteristics of each of the columns. Each component has a characteristic D and D retention time in the plane. Figure 3 (A) Single-column GC analysis result. (B) Selected incompletely resolved heartcuts from A are directed to a second column where improved separation is achieved. Here two heart-cuts are performed. (C) Illustration of multidimensional analysis GC/MS, where the second dimension is a mass spectrum recorded at the mass spectral data acquisition rate. The success of this approach depends on the uniqueness of the mass spectrum at each point in the chromatogram. (D) The comprehensive two-dimensional GC method ideally spreads out the components in a two-dimensional space, according to the characteristics of each of the columns. Each component has a characteristic D and D retention time in the plane.
The combination of GC with olfactometry is another possibility for detection that has been used in essential oils analysis. " " " Olfactometry adapters are commercially available and should include humidity of the GC effluent at the nose adapter and provide auxiliary gas flow. The correlation among eluted peaks with specific odors allows accurate retention indices or retention times to be estabhshed for the essential oil components. Some of them can be detected in this way after applying chemometric techniques, such as cluster analysis and principal component analysis, to the data from the sensors. A limitation of GC with olfactometry is that peak coelution in complex samples makes identification of the compound(s) responsible for an odor difficult, particularly where trace odorants coelute with larger odor-inactive peaks. One possible solution for identifying character-impact odorants where coelution occurs is to use comprehensive two-dimensional GC (GC X GC). " ... [Pg.812]

Debonneville C, Thome M, Chaintreau A (2004) Hyphenation of quadrupole MS to GC and comprehensive two-dimensional GC for the analysis of suspected allergens review and improvement. J Chromatogr Sci 42 450-455... [Pg.3307]

LECO Separation Science (2004) Application note no. 203-821-237 quantitative analysis of allergens in perfumes using comprehensive two-dimensional GC and time-of-llight mass spectrometry, http //www.leco.com... [Pg.3307]

The design of thermal modulation devices is undergoing rapid development because of their use in comprehensive two-dimensional GC (2DGC). Figure 5.9 illustrates some useful designs. Design (a) relies on a heater that moves along the thermal modulator column at a controlled speed in order to accelerate the band of... [Pg.243]

Cavagnino, D., Bedini, R, Zilioli, G. and Trestianu, S. (2003) Improving sensitivity and separation power by using LVSL-GCxGC-FID technique for pollutants detection at low ppb level. Poster at the Gulf Coast Conference, Comprehensive Two-Dimensional GC Symposium, 2003. [Pg.348]

LECO Separation Science, 2004, Application Note No. 203-821-237 Quantitative Analysis of Allergens in Perfumes Using Comprehensive Two-Dimensional GC andTime-of-Flight Mass Spectrometry. ... [Pg.275]


See other pages where Comprehensive two-dimensional GC is mentioned: [Pg.426]    [Pg.427]    [Pg.206]    [Pg.426]    [Pg.427]    [Pg.81]    [Pg.47]    [Pg.153]    [Pg.529]    [Pg.643]    [Pg.217]    [Pg.1840]    [Pg.1934]    [Pg.1935]    [Pg.632]    [Pg.658]    [Pg.945]    [Pg.201]    [Pg.178]    [Pg.179]    [Pg.183]   
See also in sourсe #XX -- [ Pg.202 ]




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