Temperature programmed analysis technology

Temperature-programmed analysis. (Courtesy of Agilent Technologies.)... 

Flash temperature programming is a new technique for rapidly heating capillary GC columns. The technique utilizes resistive heating of a smallbore metal sheath that contains the GC column. This technology is based on the flash GC system, an innovative chromatographic system that accomplishes in 1-2 min what takes a conventional GC from 30 min to a 1 h or more. The flash GC can be over 20 times faster than conventional GC (Fig. 11) and is also more sensitive and far more versatile. Additionally, the flash GC can be used to concentrate samples as part of its purge-and-trap capabilities. On-column cryotrapping procedures can be accomplished within the system and incorporated as part of the very fast analysis procedure. 

The user interface of this program has been rewritten completely by Biosym Technologies (currently named Accelrys, Inc., after several mergers) since its commercialization, to provide an extremely flexible and fully interactive user interface. The capabilities of this interface include the options for the user to provide designer correlations for any property of interest, to supply experimental values for three important properties (glass transition temperature, density and solubility parameter), to plot any calculated property against any other with a variety of display options, to select subsets of properties for calculation, and to obtain both the key structural descriptors and the predicted properties in a spreadsheet format (in addition to the usual output text file) to facilitate any further desired data analysis. 

GC-MS analysis was carried out using an Agilent Technology 6890 gas chromatogram coupled to a 5973 mass spectrometer fitted with a CDS 1500 valve interface held at 250°C. Separation was performed on an SGE BPX5 column (30 m length, 0.25 mm ID, and 25 pm film thickness). Helium at column flow rate of 1.1 mL/min (constant flow rate) was used as the carrier gas. Injection was splitless and injector temperature 250°C. The GC oven temperature was held for 15 min at 30°C and then programmed at 4°C/min to 300°C.The final temperature was held for 9 min. 

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