Croatica Chemica Acta, Vol. 73 No. 1, 2000.
Original scientific paper
Determination of Nonylphenol Polyethoxylates and Their Lipophilic Metabolites in Sewage Effluents by Normal-phase High-performance Liquid Chromatography and Fluorescence Detection
Marijan Ahel
; Swiss Federal Institute for Environmental Science and Technology (EAWAG), Dübendorf Switzerland
Walter Giger
; Swiss Federal Institute for Environmental Science and Technology (EAWAG), Dübendorf Switzerland
Eva Molnar
; Swiss Federal Institute for Environmental Science and Technology (EAWAG), Dübendorf Switzerland
Slavica Ibrić
; Swiss Federal Institute for Environmental Science and Technology (EAWAG), Dübendorf Switzerland
Abstract
Analytical procedures using normal-phase high-performance liquid chromatography (HPLC) with fluorescence detection, suitable for the routine determination of alkylphenol polyethoxylate (APnEO) surfactants and their lipophilic metabolites in sewage effluents at sub-microgram per litre level, have been developed. The parent nonylphenol polyethoxylates (NPnEO), covering oligomer range of 1-18 ethoxy units per molecule, were extracted from water sam-ples using solid-phase extraction on graphitised carbon black (GCB), while their lipophilic metabolites, including nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO) and nonylphenol (NP), were extracted by liquid-liquid extraction into n-hexane. The extracts were analysed by normal-phase HPLC using amino-silica columns and fluorescence detection at 228/305 nm.
This allowed reliable quantitative determination of individual oligomers down to 0.1 μg/l. Analyses of sewage effluents collected in several sewage treatment plants of the Canton of Zürich, Switzerland, indicated that NPnEO occur at significant concentrations (96-430 μg/l) despite the partial ban introduced in 1986. Oligomer distributions found in analysed sewage samples revealed that the major part of toxic lipophilic metabolites, including NP, still originate from detergent-derived NPnEO.
Keywords
nonylphenol polyethoxylates; nonionic surfactants; nonylphenol; normal-phase HPLC; sewage effluents
Hrčak ID:
132091
URI
Publication date:
1.2.2000.
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