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(38-39) Determination of NPEOn in Sewage Sludge and Compost by HPLC-MS. Fors, Jordi*,1, Bagó, Bàrbara1, Broto, Francesc1, Comellas, Lluis1, Díaz-Ferrero, Jordi1, Rodríguez-Larena, M. Carmen1, 1 Institut Químic de Sarrià, Via Augusta 390, Barcelona, Spain ABSTRACT- Alkylphenol ethoxylates are non-ionic surfactants whose commercial formulations are usually a complex mixture of homologues, oligomers and isomers. The main alkylphenols used are nonylphenol (NP) and octylphenol (OP), with nonylphenol ethoxylates (NPEOn) taking approximately 80% of the world market. The length of the ethoxylate chain varies between 1 to 50 ethoxy units. Because of their commonly utilisation in domestic and many industrial applications, toxicity and estrogenic properties, there is a growing concern for human exposure. On the other hand, the use of sewage sludge and their recycling products such as compost for soil amendment or as fertilisers is a potential source of soil contamination and consequently will result in the release of these products into the environment. The EC has elaborated the Working Document on Sludge 3rd Draft (Brussels, 27 April 2000 ENV.E3/LM) that establishes a limit value of 50 mg/kg dm for NPE in sludge for use on land (comprising nonylphenol and nonylphenol ethoxylates with 1 or 2 ethoxy units). So it is from great interest to analyse and quantify them as well as their major degradation products that can be formed under aerobic conditions. In this sense any sludge post-treatment process such as composting is a potential source of these metabolites. This work presents a fast and reliable method for the determination of NPEOn by liquid chromatography-mass spectrometry (HPLC-MS) with APCI interface in sewage sludge and compost samples. Key words: NPEOn, compost, sewage sludge, HPLC-MS |
