Analysis of non-ionics and alcohol ethoxylates. Application to confirmatory biodegradation test effluents

This paper describes a non-specific analytical procedure to evaluate total nonionic surfactants and a specific HPLC determination of alcoholethoxylates in water samples. Three different ultimate nonionic detections have been used for the nonspecific procedure: PPAS, TAS and FT 1 HNMR. Detection limits down to 5 μg/l are feasible. NMR represents a new and valid alternative to evaluate the overall content of ethoxylates measuring the -(CH 2 CH 2 O) n single signal at 6=3.65. The specific HPLC method, despite some refining is still needed, is able to determine the content of alcoholethoxylates according to their alkyl chain distribution. Each alkyl chain homolog can be detected at the sensitivity level of 1 μg/l