Probability method for pyrolysis gas chromatographic data treatment and elaboration of a computer system for the identification of polymers

Abstract

In order to develop a computer-based retrieval system for polymer identification by pyrolysis gas chromatography (Py—GC), a method for the presentation of the pyrolysis chromatograms in the form of numerical parameters is proposed in accordance with a previously described procedure. The essence of the method is the calculation of n p value, ( t p Ri) Σ, the sum of retention times for the significant peaks. The intensity of the peaks is taken into account by the parameters a 1 and a 1/ a 2 of a single mathematical function for the whole pyrolysis chromatogram F— S′ i, which where F characterizes the probability of the occurrence of a peak with a standard area S′ i. An algorithm was developed and a set of pyrolysis chromatograms in FORTRAN-4 was created. The algorithm is based on the calculation results for pyrolysis chromatograms for reference polymers and includes an interval evaluation of the parameters of polymer identification calculated from representative selections. This method for the treatment of Py—GC results characterized by low inter-laboratory reproducibility allows the preparation of a data bank in the form of a set of pyrolysis chromatograms and computer-based retrieval for polymer identification by users based on set procedures on available chromatographs and pyrolytic devices and on minicomputers or personal computers.