Direct analysis of different classes of surfactants in raw materials and in finished detergent formulations by fast atom bombardment mass spectrometry

The characterization of the components of a surfactant mixture is a challenge, since we are dealing with substances inherently difficult to purify or separate by any available chromatographic methods. The results of the present work provide evidence that with fast atom bombardment mass spectrometry it is possible to identify the single constituents of the different clases of tensides—non‐ionic, anionic, cationic and amphoteric—directly in the mixture and in detergent formulations (shampoos). The method, which is based on unambiguous molecular weight determination of the single components, allows the definition of the exact distribution of oligomers in the surfactant mixture, and distinction of subtle variations in the detergent composition in finished formulations. The results obtained indicate that this technique is a powerful analytical tool which can be used as a rapid screen test for quality control.