title: Extracting syringe for extraction of phthalate esters in aqueous environmental samples.
abstract: The use of the extracting syringe (ESy), a fully automated membrane-based extraction technique, for analysis of phthalate esters in complex aqueous samples has been investigated. The ESy, working as an autosampler that combines the extraction process and injection into the gas chromatograph (GC) in one single step, is placed on top of the GC equipped with a flame ionisation detector. The aqueous samples are loaded in a tray and automatically extracted by employing microporous membrane liquid-liquid extraction principle. After the extraction, the extract is directly injected into the GC's programmable temperature vaporisation injector. Six different phthalate esters were used as model compounds. Four extraction solvents were tested and the addition of sample organic modifier was examined. Toluene was the optimal solvent to use for extraction. Due to the large variation in polarity of phthalate esters, 50% methanol as organic modifier had to be added to the samples so as to extract the most nonpolar phthalate esters; di-2-ethylhexylphthalate and di-n-octylphthalate, whereas the other four relatively polar phthalate esters were extracted from unmodified samples. No significant difference between extraction of river water, leachate water from a landfill and reagent water was noted, except for minor deviations. The extraction time was 20 min for extraction of a 1-mL sample, resulting in a good linearity for all aqueous media investigated, good enrichment factors (54-110 folds) and low LOD values (0.2-10 ng mL(-1)) and relative standard deviation (%R.S.D.; 0.9-3.7%).
authors.affiliation: Department of Analytical Chemistry, Lund University, P.O. Box 124, S-221 00 Lund, Sweden.
authors.forename: Staffan
authors.initials: S
authors.lastname: Bergström
authors.forename: Thaer
authors.initials: T
authors.lastname: Barri
authors.forename: Jan
authors.initials: J
authors.lastname: Norberg
authors.forename: Jan Ake
authors.initials: JA
authors.lastname: Jönsson
authors.forename: Lennart
authors.initials: L
authors.lastname: Mathiasson
mesh_terms: D002849:Chromatography, Gas; D004784:Environmental Monitoring / Q000295:instrumentation*; D010795:Phthalic Acids / Q000032:analysis*; D045483:Rivers; D013594:Syringes; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010795:Phthalic Acids; D014874:Water Pollutants, Chemical