Determination of anionic and nonionic surfactants, their degradation products, and endocrine-disrupting compounds in sewage sludge by liquid chromatography/mass spectrometry

A comprehensive analytical method based on reversed-phase liquid chromatogr aphy and mass spectrometry using both atmospheric pressure chemical ionizat ion and electrospray ionization has been developed for the simultaneous det ermination of anionic and nonionic surfactants, their polar degradation pro ducts, and endocrine-disrupting compounds (EDCs) in sewage sludge; Extracti on of target compounds, with recovery rates from 86% to nearly 100% for pol yethoxylates and from 84 to 94% for polar degradation products, was achieve d applying ultrasonic solvent extraction with a mixture of methanol/dichlor omethane (7:3, v/v), Cleanup of sample extracts was performed on octadecyl solid-phase extraction cartridges. Determination of less polar compounds: a lcohol ethoxylates (AEOs), nonylphenol ethoxylates (NPEOs), coconut diethan ol amides, poly(ethylene glycol)s, and phthalate esters was accomplished by reversed-phase LC-APCI-MS in positive ionization mode, while more polar co mpounds: nonylphenolcarboxylates, nonylphenol (NP), octylphenol, and bisphe nol A were analyzed by ion-pair LC-ESI-MS under negative ionization conditi ons. This protocol was successfully applied to the trace determination of a nionic and nonionic surfactants, polar degradation products, and EDCs in se wage sludge collected from different sewage treatment plants, The analysis revealed the presence of NP at high concentration levels ranging from 25 to 600 mg/kg, Polyethoxylates (AEOs and NPEOs) were also found in all samples at parts-per-million levels (10-190 mg/kg AEOs and 2-135 mg/kg NPEOs, resp ectively).