The past decade has been characterized by an evolution from electronic-regulated to computer-controlled analytical equipment. This holds especially true for spectroscopic instruments, e.g. FT-IR spectrometers and FT-NMR spectrometers, where the application of Fourier transform techniques requires computer support. But Chromatographic instruments are nowadays also equipped with dedicated computers or PCs for controlling the instrument and for data acquisition and evaluation.
The development has led to an improved performance of the instruments in terms of enhanced information, sensitivity, and reliability. These modern analytical instruments can be used favorably for the analysis of coatings and coating materials, making them a valuable tool for the analyst working in this field. In this paper the most important methods will be described and illustrated with examples from daily work.
Since coating materials very often represent complex mixtures, in some cases the combination of different instrumental methods is necessary to obtain the required information. Examples that will be dealt with are pyrolysis-GC/MS and the coupling of Chromatographic and spectroscopic methods, e.g. GPC/FT-IR or GPC/FT-NMR.
In many cases a work-up procedure as a preparatory step prior to the instrumental method is advisable in order to achieve sufficient information. Since many of the coating materials contain saponifiable groups, saponification is still the most prominent method. A general scheme for carrying out such a saponification will be outlined. In addition, we would also like to demonstrate a recently developed method using trimethylsulfonium hydroxide as the reagent. This method, which can be easily applied in the same way as the well-known GC derivatization procedures, yields more reliable results for fatty acids and polyols than the conventional method.