title: Equilibrium in-fibre standardisation technique for solid-phase microextraction.
abstract: This note describes a fundamental investigation into solid-phase microextraction (SPME) using a standard loaded into the fibre coating as a means of internal standardisation for the analysis of samples contained in vials. The loading of reproducible amounts of standards into a non-porous SPME fiber was investigated. It was found that spiking low milligram quantities of standards such as benzene, toluene, ethylbenzene, xylenes (BTEX) and/or naphthalene into a few grams of pump oil sealed in a 20 mL vial provided an excellent standard generator. A single solution allowed over a hundred standard loadings with a reproducibility of <4% R.S.D. When a fiber, loaded with the standard(s) was introduced into a sample vial, extraction of analytes into the fiber and desorption of the standard(s) into the sample matrix occur simultaneously. Quantification was then based on the equilibrium distribution of the standards and the analytes between the fibre coating and the sample matrix in the vial. A comparison of equilibration profiles obtained using traditional internal standardisation and the in-fibre approach generally showed the same equilibration behaviour. The developed method was successfully used to correct for matrix effects in the BTEX analysis of a wine sample.
authors.affiliation: Department of Chemistry, University of Waterloo, Waterloo, Ont., Canada N2L 3G1.
authors.forename: Yanxiang
authors.initials: Y
authors.lastname: Wang
authors.forename: John
authors.initials: J
authors.lastname: O'Reilly
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Janusz
authors.initials: J
authors.lastname: Pawliszyn
mesh_terms: D001331:Automation; D001554:Benzene / Q000302:isolation & purification; D001555:Benzene Derivatives / Q000302:isolation & purification; D002138:Calibration; D002849:Chromatography, Gas / Q000379:methods*; D008433:Mathematics; D008832:Microchemistry / Q000379:methods; D009281:Naphthalenes / Q000302:isolation & purification; D012015:Reference Standards; D014050:Toluene / Q000302:isolation & purification; D014920:Wine / Q000032:analysis; D014992:Xylenes / Q000302:isolation & purification
chemical_list: D001555:Benzene Derivatives; D009281:Naphthalenes; D014992:Xylenes; C031721:naphthalene; D014050:Toluene; D001554:Benzene; C004912:ethylbenzene; C026114:2-xylene