title: Determination of decamethylcyclopentasiloxane in river and estuarine sediments in the UK.
abstract: Robust analytical procedures for the measurement of decamethylcyclopentasiloxane (D₅) in river and estuarine sediments and their application in determining environmental concentrations in the UK are presented for the first time in this work. Novel approaches to minimise commonly reported artefacts are utilised, improving the confidence in the concentrations of D₅ reported. Accelerated solvent extraction (ASE) and liquid-solid extraction methods are compared. Both methods use on-column injection gas chromatography/mass spectrometry (GC/MS). Measurements of D₅ concentrations in sediments sampled from the river Great Ouse and from the Humber estuary (UK) are also reported. ASE was suitable to measure concentrations of D₅ in sediments obtained from the river Great Ouse, UK (186-1450 ng g⁻¹, dry weight) and octamethyltetracyclosiloxane (D₄, 12-24 ng g⁻¹, dry weight). C₁₂ linear alkybenzene (C₁₂ LAB), which can be used as a chemical marker for sewage effluent related emissions, was also measured in this analysis. Liquid-solid extraction was optimised to provide more confidence in the lower D₅ concentrations measured in the Humber estuary, UK (49-256 ng g⁻¹, dry weight). A Limit of quantitation (LOQ) for D₅ of 57-110 and 4 ng g⁻¹ dry weight was determined for ASE and liquid-solid extraction, respectively.
authors.affiliation: Safety & Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK441LQ, United Kingdom. chris.sparham@unilever.com
authors.forename: Chris
authors.initials: C
authors.lastname: Sparham
authors.forename: Roger
authors.initials: R
authors.lastname: van Egmond
authors.forename: Colin
authors.initials: C
authors.lastname: Hastie
authors.forename: Sean
authors.initials: S
authors.lastname: O'Connor
authors.forename: Dave
authors.initials: D
authors.lastname: Gore
authors.forename: Namrata
authors.initials: N
authors.lastname: Chowdhury
mesh_terms: D005591:Chemical Fractionation; D004785:Environmental Pollutants / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D019015:Geologic Sediments / Q000737:chemistry*; D015203:Reproducibility of Results; D045483:Rivers / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012833:Siloxanes / Q000032:analysis*; D006113:United Kingdom
chemical_list: D004785:Environmental Pollutants; D012833:Siloxanes; C114768:decamethylcyclopentasiloxane