Caracterización y determinación de surfactantes y otros componenetes en productos de limpieza con aplicación en control de calidad de formulaciones industriales.

by Bernabé Zafón, Virginia

ABSTRACT The resolution of mixtures of surfactants using capillary electrophoresis (CE) with spectrophotometric detection was studied. A procedure capable to separate, characterise and determine mixtures of alkyl ether sulfates and fatty acids in cleaning products was developed. Mixtures of the previous surfactants with alkyl benzene sulphonates (ABS) were also resolved. In order to resolve the mixtures, simple experimental methods were employed, but also alternative chemometric tools were used. The separation of other nonionic and zwitterionic surfactants with the ABS was also developed optimizing the experimental conditions, and using chemometric procedures that improved the resolution and assured the identification of the peaks to the surfactant class. Fatty alcohol ethoxylated are probably the most important nonionic surfactants. The detection of these surfactants in mass spectrometry (MS) without previous derivatisation was studied. The response factors of the oligomers by direct infusion in several media were examined. In the optimum medium, models of the response factors were established. The MS detection was shown to be compatible with a previous chromatographic or electrophoretic separation. The non ethoxylated alcohol showed an extremely low sensitivity which hindered its calibration. Primary alcohols and alcohol ethoxylates were oxidized to carboxylic acids to enhance sensitivity. The oxidation was quantitative for primary alcohols but the oxidation yield was lower than 100 % for alcohols ethoxylates. Application to the analysis of primary alcohols in cosmetic products was demonstrated. The alkylpolyphosphonates (APPs) are additives present in cleaning products. They were characterised by direct infusion in mass spectrometry. The spectra revealed the presence of impurities with fewer phosphonate groups than those corresponding to the nominal compounds. Using MS2 and MS3 studies the degradation pathways were satisfactorily explained. A CE-MS method was used to guarantee the presence of impurities. Finally, a CE with indirect photometric detection was developed to rapid characterisation of APPs. Also the resolution of the CE-MS method was improved. The CE-MS method was applied to the determination of APPs in cleaning products.