Sorption And Analysis Of Some Nonylphenol Ethoxylate Surfactants On Wool
A simple method has been devised to analyze a common type of nonionic surfactant (nonylphenol ethoxylate with an average of 8-15 ethylene oxide units) on wool. The advantages of this method are its insensitivity to the presence of processing oils and wool grease and its ability to detect concentrations as low as 0.02% on wool. The method involves isocratic, high-pressure liquid chromatography on a diol-bonded silica column. The amount of surface surfactant is determined from a dichloromethane extract of a dried wool sample, and the total amount of surfactant is found from a 40°C methanol extract of another wool sample. This method follows the adsorption and desorption of two nonylphenol ethoxylate surfactants from aqueous solution onto wool under various conditions, as well as the diffusion of one of these surfactants from the surface into wool fibers.