title: Determination of cyclic volatile methylsiloxanes in water, sediment, soil, biota, and biosolid using large-volume injection-gas chromatography-mass spectrometry.
abstract: Several methods were developed to detect the cyclic volatile methylsiloxanes (cVMSs) including octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in water, sediment, soil, biota, and biosolid samples. Analytical techniques employed to optimize measurement of this compound class in various matrices included membrane-assisted solvent extraction in water, liquid-solid extraction for sediment, soil, biota, and biosolid samples. A subsequent analysis of the extract was conducted by large-volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). These methods employed no evaporative techniques to avoid potential losses and contamination of the volatile siloxanes. To compensate for the inability to improve detection limits by concentrating final sample extract volumes we used a LVI-GC-MS. Contamination during analysis was minimized by using a septumless GC configuration to avoid cVMS's associated with septum bleed. These methods performed well achieving good linearity, low limits of detection, good precision, recovery, and a wide dynamic range. In addition, stability of cVMS in water and sediment was assessed under various storage conditions. D4 and D5 in Type-I (Milli-Q) water stored at 4°C were stable within 29d; however, significant depletion of D6 (60-70%) occurred only after 3d. Whereas cVMS in sewage influent and effluent were stable at 4°C within 21d. cVMS in sediment sealed in amber glass jars at -20°C and in pentane extracts in vials at -15°C were stable during 1month under both storage conditions.
authors.affiliation: Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, Burlington, ON, Canada L7R 4A6.
authors.forename: De-Gao
authors.initials: DG
authors.lastname: Wang
authors.forename: Mehran
authors.initials: M
authors.lastname: Alaee
authors.forename: Helena
authors.initials: H
authors.lastname: Steer
authors.forename: Tara
authors.initials: T
authors.lastname: Tait
authors.forename: Zackery
authors.initials: Z
authors.lastname: Williams
authors.forename: Samantha
authors.initials: S
authors.lastname: Brimble
authors.forename: Lewina
authors.initials: L
authors.lastname: Svoboda
authors.forename: Enzo
authors.initials: E
authors.lastname: Barresi
authors.forename: Maryl
authors.initials: M
authors.lastname: Dejong
authors.forename: Joanne
authors.initials: J
authors.lastname: Schachtschneider
authors.forename: Ed
authors.initials: E
authors.lastname: Kaminski
authors.forename: Warren
authors.initials: W
authors.lastname: Norwood
authors.forename: Ed
authors.initials: E
authors.lastname: Sverko
mesh_terms: D058448:Biota; D004784:Environmental Monitoring / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D019015:Geologic Sediments / Q000737:chemistry; D012722:Sewage / Q000737:chemistry; D012833:Siloxanes / Q000032:analysis*; D012987:Soil / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D012722:Sewage; D012833:Siloxanes; D012987:Soil; D014874:Water Pollutants, Chemical; C114768:decamethylcyclopentasiloxane; C024064:octamethylcyclotetrasiloxane; C542115:dodecamethylcyclohexasiloxane