title: Combined supercritical-fluid chromatography/mass spectrometry in the analysis of diuron in plasma using on-line phase-system switching.
abstract: On-line sample pretreatment by means of the phase-system switching approach is an interesting technique for the analysis of aqueous samples, e.g., plasma, by means of supercritical-fluid chromatography. In order to analyse plasma samples the following analytical procedure is used. The plasma sample is injected on to a short precolumn, which is washed with water and subsequently dried with nitrogen. Next, the solutes are desorbed with the supercritical mobile phase, analysed with packed-column supercritical-fluid chromatography and detected with either a UV detector or a mass spectrometer, equipped with a moving-belt interface. The herbicide diuron is selected as a test compound to study the feasibility of this approach. Using a selective detector the procedure is sufficiently sensitive to detect diuron in plasma, but not appropriate to detect the diuron metabolites in a post-mortem plasma sample. These have been identified with liquid chromatography/mass spectrometry. The detection limit of diuron in plasma using the procedure described is about 30 ng/mL.
authors.affiliation: Division of Analytical Chemistry, Center for Bio-Pharmaceutical Sciences, Leiden, The Netherlands.
authors.forename: W M
authors.initials: WM
authors.lastname: Niessen
authors.forename: M A
authors.initials: MA
authors.lastname: de Kraa
authors.forename: E R
authors.initials: ER
authors.lastname: Verheij
authors.forename: P J
authors.initials: PJ
authors.lastname: Bergers
authors.forename: G F
authors.initials: GF
authors.lastname: La Vos
authors.forename: U R
authors.initials: UR
authors.lastname: Tjaden
authors.forename: J
authors.initials: J
authors.lastname: van der Greef
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004237:Diuron / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques; D013058:Mass Spectrometry / Q000379:methods
chemical_list: D004237:Diuron