Pyrolysis in Biotechnology

Abstract

Pyrolysis is the thermal decomposition of molecules in an inert atmosphere. The transfer of thennal energy to a polymeric network or to macromolecules causes degradation of the sample into volatile products. The reaction products are characteristic ofthe original structure and much more easily analysed than the original sample. A significant advantage of the pyrolysis technique is the speed of the analysis~ Complex materials that normally require time consuming analysis can be investigated by this technique coupled to gas chromatography (Py-GC) in less than an hour or with it coupled directly to a mass spectrometer (Py-MS) in a couple of minutes. e.G. Williams' article from 1862 is considered to be the first of its kind in the field of pyrolysis. That study identified isoprene as the main pyrolytic product of robber. However, broad use of analytical pyrolysis has had to wait for the development of modern analytical technology. Today, pyrolysis is widely used to study macro.. molecules, including synthetic and natural polymers (see for example Wampler, 1989), to perform degradation and kinetic studies and also for the qualitative and quantitative analysis of complex substances. Examples of material analysed by pyrolysis are synthetic polymers (for a review, see Blazs6, 1997), coating materials (Haken, 1999), rubber (Dubey et aI., 1995), paper and paper coating, plant material (Ralph and Hatfield, 1991) and bacteria. Pyrolysis is also used in forensic science, art and archaeology (Shedrinsky et aI., 1989). This present review focuses on the analytical pyrolysis of biological macromolecules such as proteins, DNA and microorganisms. The first part of the article presents an overview of the pyrolysis techniques available and the methods for analysis of the pyrolytic products, the pyrolysate. The second part presents some applications to illustrate the types ofproblem that researchers have been able to solve using pyrolysis.