ABSTRACT
The nonionic surfactants, alkylphenol ethoxylates, have the highest production rates among the surfactants used in industrial and domestic applications. Although the domestic applications of these compounds have declined significantly in recent years, their use in industrial detergents and other industrial processes such as wool washings have continued unabatedly. Phenol ethoxylates are also used in paints, agrochemicals, emulsion polymers, textiles, and metal finishing and, sometimes, as antioxidants in plasticizers. Alkylphenol ethoxylate surfactants are usually made from the branched-chain alkylphenols, mostly nonylphenol (NP) and octylphenol by reactions with ethylene oxide. In commercial formulations that are usually complex mixtures of homologues, oligomers, and isomers, the length of the ethoxylate chain varies between 1 and 50 ethoxy units, depending on the use. These substances biodegrade in the environment producing alkylphenol monoethoxylates and diethoxylates, alkylphenol acetic acids, alkylphenolpolyethoxyacetic acids, and alkylphenols. Emerging pollutants may be determined by liquid chromatography/mass spectrometry (LC/MS) or gas chromatography/MS (GC/MS) following their extractions from water, soil, and sediments.
