title: Strategies for selecting optimal sampling and work-up procedures for analysing alkylphenol polyethoxylates in effluents from non-activated sludge biofilm reactors.
abstract: Trace-level analysis of alkylphenol polyethoxylates (APEOs) in wastewater containing sludge requires the prior removal of contaminants and preconcentration. In this study, the effects on optimal work-up procedures of the types of alkylphenols present, their degree of ethoxylation, the biofilm wastewater treatment and the sample matrix were investigated for these purposes. The sampling spot for APEO-containing specimens from an industrial wastewater treatment plant was optimized, including a box that surrounded the tubing outlet carrying the wastewater, to prevent sedimented sludge contaminating the collected samples. Following these changes, the sampling precision (in terms of dry matter content) at a point just under the tubing leading from the biofilm reactors was 0.7% RSD. The findings were applied to develop a work-up procedure for use prior to a high-performance liquid chromatography-fluorescence detection analysis method capable of quantifying nonylphenol polyethoxylates (NPEOs) and poorly investigated dinonylphenol polyethoxylates (DNPEOs) at low microg L(-1) concentrations in effluents from non-activated sludge biofilm reactors. The selected multi-step work-up procedure includes lyophilization and pressurized fluid extraction (PFE) followed by strong ion exchange solid phase extraction (SPE). The yields of the combined procedure, according to tests with NP10EO-spiked effluent from a wastewater treatment plant, were in the 62-78% range.
authors.affiliation: Quality Control Support, GE Healthcare, Bio-Sciences AB, Björkgatan 30, S-751 84 Uppsala, Sweden. ake.stenholm@ge.com
authors.forename: Ake
authors.initials: A
authors.lastname: Stenholm
authors.forename: Sara
authors.initials: S
authors.lastname: Holmström
authors.forename: Sandra
authors.initials: S
authors.lastname: Hjärthag
authors.forename: Ola
authors.initials: O
authors.lastname: Lind
mesh_terms: D018441:Biofilms; D019149:Bioreactors; D002851:Chromatography, High Pressure Liquid; D010636:Phenols / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D012722:Sewage / Q000032:analysis*; D052616:Solid Phase Extraction; D021241:Spectrometry, Mass, Electrospray Ionization; D013501:Surface-Active Agents / Q000032:analysis
chemical_list: D010636:Phenols; D012722:Sewage; D013501:Surface-Active Agents; D011092:Polyethylene Glycols