Fast GC analysis

Fig. 1 Fast GC analysis of aviation turbine engine fuel using a typical laboratory GC instrument. Conditions hydrogen carrier gas temperature programming rate, 70-170°C at 120°C/min (actual 75°C/min) microbore column 3 m x 0.10 mm ID.

Fig. 3 Fast GC analysis of four fuels including (a) JP-8 (b) JP-7 (c) JP-TS and (d) diesel fuel.

Hgure 3 Fast-GC analysis of lime essential oil using a 5m X 50pm capillary column with 0.05pm d, with hydrogen as the carrier gas. One microliter of a 1% essential oil in n-hexane solution was injected using a split ratio of 750 1. The column head pressure was 880 kPa and the GC oven was temperature programmed from 50 to 150°C at 80°Cmin" , to 200°C at 70°C min, and finally to 250°C at 55°Cmin" . 

Another important consideration of the GC oven in fast-GC analysis is the cool-down period. Indeed, the total analysis time should take into consideration the GC runtime, the oven cool-down period, and also the sample preparation step. Automated sample preparation, often in large batches, is becoming increasingly popular, reducing this part of the total analysis time. Thus, maximum time efficiency will require the shortest possible oven cool-down and equilibration time. Modern GC equipment is constructed of lightweight material to assist in heat transfer from the oven walls to the oven air, which is... 

FIGURE 6.2 Fast GC analysis of a lime essential oil on a 5 m x 5 mm (0.05 pm film thickness) capillary column, applying fast temperature programming. The peak widths of three components are marked to provide an illustration of the high efficiency of the column, even under extreme operating conditions (for peak identification see on Ref. [50]). (From Mondello, L. et al., 2004. J. Sep. ScL, 27 699-702. With permission.)... 

Bias Y, Bieri S, Christen P, Veuthey J-L (2006) Evaluation of Solid-Phase Microextraction Desorption Parameters for Fast GC Analysis of Cocaine in Coca I-eaves. J Chromatogr Sci 44 (Copyright (C) 2012 American Chemical Society (ACS). All Rights Reserved.) 394-398... 

Table 2.30 Capillary column dimensions that can be replaced 1 1 in order to achieve fast GC analysis.

Principles and Characteristics As mentioned already (Section 3.5.2) solid-phase microextraction involves the use of a micro-fibre which is exposed to the analyte(s) for a prespecified time. GC-MS is an ideal detector after SPME extraction/injection for both qualitative and quantitative analysis. For SPME-GC analysis, the fibre is forced into the chromatography capillary injector, where the entire extraction is desorbed. A high linear flow-rate of the carrier gas along the fibre is essential to ensure complete desorption of the analytes. Because no solvent is injected, and the analytes are rapidly desorbed on to the column, minimum detection limits are improved and resolution is maintained. Online coupling of conventional fibre-based SPME coupled with GC is now becoming routine. Automated SPME takes the sample directly from bottle to gas chromatograph. Split/splitless, on-column and PTV injection are compatible with SPME. SPME can also be used very effectively for sample introduction to fast GC systems, provided that a dedicated injector is used for this purpose [69,70],... 

The use of stable, narrow-bore columns and fast oven temperature programmes result in analysis times of 5-15min, while maintaining the final resolution obtained with conventional GC approaches. Fast GC-MS (5-200 s) requires the matching of several technologies ... 

On-line SFE-GC-MS was used for the analysis of organic extractables from human hair [312]. Van Lieshout et al. [313] described GC-MS analysis of an SFE extract of an (ABS) impact-modified PC/PBT blend identifying Ionol CP, Dressinate, cyclic PBT trimer, Irganox 1076 and Irganox PS 800. TD-GC-MS was used in the development of flame retardants, and for the analysis of fire debris [314]. The application of laser desorption fast GC-MS analysis was employed in the analysis of DOP on a stainless-steel surface [221]. 

The use of GC-MS in polymer/additive analysis is now well established. Various GC-based polymer/additive protocols have been developed, embracing HTGC-MS, GC-HRMS and fast GC-MS with a wide variety of front-end devices (SHS, DHS, TD, DSI, LD, Py, SPE, SPME, PTV, etc.). Ionisation modes employed are mainly El, Cl (for gases) and ICPI (for liquid and solid samples). Useful instrumental developments are noticed for TD-GC-MS. GC-SMB-MS is a fast analytical tool as opposed to fast chromatography only [104]. GC-ToFMS is now about to take off. GC-REMPI-MS represents a 3D analytical technique based on compound-selective parameters of retention time, resonance ionisation wavelength and molecular mass [105]. 

With recent instrumental development, such as fast LC, fast GC and two-dimensional gas chromatography (GCxGC) and advanced tandem hybrid MS detection systems (i.e., QqTOF, QqLIT, Orbitrap) the analysis of complex mixtures... 

Table 11.2 enlists analytical techniques employed in the two screening stages. From the table it is evident that there are a lot of parallel or quasiparallel analysis techniques but fewer techniques that are employed in a fast sequential mode. Evidently, rapid GC analysis is in the focus of Stage II screening as the most useful analytical technique. 

Gorecki, T. and PawUszyn, J. 1997, Eield-portable solid-phase microextraction/fast GC system for trace analysis. Field Anal. Chem. Tech. 1 227—284. 

Mondello, L., Casilli, A., Tranchida, P.Q., Cicero, L., Dugo, R, Dugo, G. (2003) Comparison of fast and conventional GC analysis for citrus essential oils. J. Agric. Food Chem. 

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