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2A - Mixture toxicity (MOP/75) Analysis of effluent samples for alcohol ethoxylates: An ERASM monitoring study. Eadsforth, Charles1, Matthijs, Eddy2, Sherren, Andrew1, Selby, Martin1, 1 Shell, Chester, UK2 Procter & Gamble, Brussels, Belgium ABSTRACT- A monitoring study was initiated by ERASM to collect and analyse effluent samples from sewage treatment plants in Europe. In Phase 1, three effluents from both the Netherlands and UK were sampled over a 24 hour period in a flow proportional mode. Sampling of effluents from three other countries (Phase 2) is underway. Plants were well-managed activated sludge works receiving <30% industrial input with no other secondary or tertiary treatment. The fully validated method analyses individual components by carbon numbers, C12, C13, C14, C15, C16 and C18, and ethoxylate numbers 0 (fatty alcohol) to 18. The limits of quantitation for the 114 analytes in deionised water ranged from 0.2-9 ng/l, equivalent to a total alcohol ethoxylate (AE) content of 0.25 Key words: environmental fingerprint, alcohol ethoxylates, effluents, lc/ms analysis |
g/l. Effluents samples (4 litres) were drawn through washed C2 solid phase cartridges. After drying, the AEs were eluted through ion-exchange cartridges, firstly with acetonitrile, then with a mixture of methanol and ethyl acetate. The second fraction was evaporated, the two fractions combined, fortified with internal standard and derivatised with 2-fluoro-N-methyl pyridinium toluene sulphonate. The reaction mixture was blown to dryness, redissolved in mobile phase and analysed by LC/MS in positive ion electrospray mode. Quantitation was by calibration with derivatised AE standards corrected for internal standard response. Mean recovery of the analytes was 75.0 +/- 31.1 %. Analysis of replicate extractions (n=4) and replicate injections of a single extract (n=3) had RSD (%) of 13 and 8 respectively. Total AE concentrations in Dutch and UK samples ranged from 5.4-8.2