Pyrolysis Gas Chromatography

In order to attain that goal, thermal fragmentation of such samples was proposed with the object of providing volatile products that would yield to conventional gas chromatographic separation. Having identified the resultant products and made the basic assumption that the fragmentation of the sample was complete, one then had to reassemble the jigsaw in order to elucidate the nature, even the identity, of the original sample. In any event, meaningful deduction must be implicit with the base assumption that one is considering primary degradation products, hence, pre-knowledge of the character and/or chemistry of a particular sample is often needed in order to arrive at a definitive conclusion.

Naturally, thermal degradation is a method that requires educated application in that resultant fragments must be of a molecular size that allows sensible interpretation. Obviously, a large number of small fragments are of little value since ultimately most organics will break down to very light hydrocarbons, both saturated and unsaturated, carbon oxides, water and a variety of inorganics of greater volatility, e.g. ammonia, hydrogen chloride, oxides of nitrogen or sulfur.

Although Davison, Slaney and Wragg are credited with the introduction of pyrolysis gas chromatogra-phy (PGC) in 1954, there is ample evidence that several workers were developing the method even earlier. It was immediately recognized that the technique was invaluable for the identification of synthetic polymers whose commercial viability depended on suppression of their chemical identities. Thus there was a good reason to conceal the fact that one could not only access competitors' products but learn as much or even more about a particular product than the manufacturer!

Whatever has been said and written about slow pyrolysis is very much open to question. Certain workers have long advocated the use of slow temperature ramps to reveal progressive transitions in the sample. It does not seem unreasonable to suggest that the approach is untenable as homogeneity of the sample is imperilled. Heat transfer within that sample and variable rates of diffusion of any products through unaffected, untransformed, undegraded, affected, transformed or degraded sample cannot be controlled and therefore leaves the question 'what is one actually looking at?' unanswered.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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