title: Assessment of polycrystalline graphites as sorbents for solid-phase microextraction of nonionic surfactants.
abstract: Two polycrystalline graphites (pencil lead and glassy carbon) were used as sorbents for solid-phase microextraction of a nonionic alkylphenol ethoxylate surfactant (Triton X-100). Analyses were performed by reversed-phase HPLC-fluorescence detection. The presence of the benzene ring in the congeners of Triton X-100 also allowed their direct detection at lambda(ex) = 230 nm and lambda(em) = 310 nm. Variables such as time of adsorption, time of desorption and concentration of surfactant in water were evaluated. The method limit of detection was found to be 0.5 microg/l for Triton X-100, with a linear dynamic range of 0.5-150 microg/l. Results were compared to those obtained using polymeric fibers such as PDMS/DVB and Carbowax/TPR. The chemical resistance and low cost of the polycrystalline graphites are advantageous over commercially available SPME fibers.
authors.affiliation: Center for Analytical and Environmental Chemistry, Chemistry Department, Carleton University, Ottawa, ON, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Aranda
authors.forename: P
authors.initials: P
authors.lastname: Kruus
authors.forename: R C
authors.initials: RC
authors.lastname: Burk
mesh_terms: D006108:Graphite / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D017830:Octoxynol / Q000737:chemistry / Q000302:isolation & purification*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D006108:Graphite; D017830:Octoxynol