Determination of decamethylcyclopentasiloxane in river water and final effluent by headspace gas chromatography/mass spectrometry

A method is described for the analysis of decamethylcyclopentasiloxane (D5) in river water and treated waste water using headspace gas chromatography/mass spectrometry. Internal standard addition to samples and field blanks was carried out in the field to provide both a measure of recovery and to prevent any exposure of samples to laboratory air, which contained background levels of D5. Measured levels of D5 were typically in the range <10–29 ng L−1 in the River Great Ouse (UK) with slightly higher levels in the River Nene (UK). The measured concentration of D5 in treated waste water varied between 31 and 400 ng L−1, depending on the type of treatment process employed.