Derivatization LC/MS for the simultaneous determination of fatty alcohol and alcohol ethoxylate surfactants in water and wastewater samples

A new LC/MS method has been developed for the simultaneous measurement, in water and wastewater samples, of all species contained in commercial sample s of linear type of alcohol ethoxylate (AE) surfactants including fatty alc ohols. The method requires derivatization of the terminal hydroxyl of each surfactant species with 2-fluoro-N-methylpyridinium p-toluenesulfonate, whi ch imparts a permanent cationic charge, allowing all species including the fatty alcohols and those with only one ethoxylate to be effectively detecte d by electrospray MS. Detection limits of typically <10 ppt for each indivi dual species were attained in treated wastewater, in which total AE concent rations (combination of up to 114 individual species) are not expected to e xceed 10 ppb. The method was validated for clean water as well as sewage in fluent and effluent samples.