Analytical characterization of natural waxes employing pyrolysis-gas chromatography-mass spectrometry

Three natural waxes (bleached beeswax, lanolin, yellow carnauba wax) were i nvestigated by means of pyrolysis-gas chromatography-mass spectrometry (Py- GC-MS). Pyrograms were obtained showing very characteristic signal patterns . Mass spectrometric detection enabled the structural identification of the pyrolytically formed fragments. For a more detailed investigation of the t hermal degradation behaviour of waxy materials, relevant model compounds we re selected. Hexadecylpalmitate, cholesterylstearate, heptadecanoic acid an d 1-hexacosanol were examined under identical Py-GC-MS conditions. From the resulting product distribution general statements were able to be derived according to the thermal degradation pathways of typical wax constituents. The findings obtained from the model compounds were then applied to the int erpretation of the real wax pyrograms. As a result, conclusions according t o their origin from corresponding wax constituents were drawn for the major ity of pyrolysis products. Thus, the extended potential of the method for t he compositional analysis of natural waxes is demonstrated. (C) 1999 Elsevi er Science B.V. All rights reserved.