Sample preparation thermodesorption

Apart from thermodesorption, all other sample preparation techniques are normally directed toward production of a liquid extract that is subsequently injected into a GC/MS system. For the simplest of the samples, neat organic liquids or concentrated solutions, the sample preparation method will consist of diluting the sample with a suitable, clean solvent (most often dichloromethane). 

GC, preferably with MS coupling and sample preparation (extraction, purge trap, spray trap, solid phase extraction (SPE), solid phase microextraction, headspace, thermodesorption, soil air trap], nondispersive infrared spectroscopy (NDIR). FT-IR, TLC, immunoassays and biosensors (for determination of defined substances)... 

M. Rothaupt, Thermodesorption as sample preparation technique for food and flavor analysis by gas chromatography, Flavor Analysis. Developments in Isolation and Characterization (C. J. Mussinan and M. J. Morello, eds.), American Chemical Society, Washington, DC, 1998, p. 116. 

A good-quality CeMCM-41 material with Si/Ce=50 was synthesized by hydrothermal method. For the purpose of comparison a pure siliceous MCM-41 was prepared using the same composition without cerium. Thermogravimetric curves for the synthesized uncalcined samples exhibit shape characteristic for the MCM-41-type materials. The specific surface area of CeMCM-41 evaluated from nitrogen adsorption was equal to 850 m2/g, whereas the pore width and mesopore volume of this material were equal to 3.8 nm and 0.8 cm3/g, respectively. In contrast to the pure silica MCM-41, the CeMCM-41 material exhibits medium and strong acid sites as revealed by thermogravimetric studies of n-butylamine thermodesorption. 

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