A sensitive and robust method for the determination of alkylphenol polyethoxylates and their carboxylic acids and their transformation in a trickling filter wastewater treatment plant

摘要

This paper presents a method for the determination of alkylphenols, alkylphenol polyethoxylates (APEO) and alkylphenol ethoxycarboxylates (APEC) in the aqueous and particulate phase of wastewater samples. Quantification was achieved by liquid chromatography tandem mass spectrometry. The sensitivity of the method is demonstrated by low detection limits, in the dissolved phase 1.2 to 9.6 ng L-1 for alkylphenol, AP1-3EO and APEC and 0.1 – 4.1 ng L-1 for longer chain alkylphenol polyethoxylates. The method detection limit for particulate phase samples ranged from 6 to 60 ng g-1 for AP, AP1-3EO and APEC; with the longer chain APEO being from 0.5 – 20 ng g-1. Matrix effects were noted in complex matrix rich samples. There was a distinct change in the distribution of alkylphenol ethoxylates during biological treatment of the wastewater, with the major biotransformation products observed being carboxylated derivatives at concentrations of up to 1768 ng L-1. Shorter chain APEO were present in higher proportions in the suspended solids, due to their higher affinity to particulate matter compared to the long chain oligomers.