title: Separation of divalent transition metal beta-diketonates and their adducts by supercritical fluid chromatography.
abstract: A method for separation and detection of divalent transition metal beta-diketonates by adduct formation/supercritical fluid chromatography (SFC) with an open-tubular capillary column and a FID detector is described. The crystal structures of copper (Cu)-hexafluoro-acetylacetone (HFA) and Cu bis(2,2,6,6-tetramethyl-3,5-heptanedionato) (THD) complexes have been determined by X-ray crystallography. The SFC behavior of Cu beta-diketonates shows a strong correlation with the structure of the complexes. The hydrated cu beta-diketonate complexes usually exhibit strong intermolecular interactions or decomposition in SFC. Formation of adducts with a neutral donor, such as tributyl phosphine oxide (TBPO), can greatly improve the SFC behavior and detection sensitivity of Cu(II) and Mn(II) beta-diketonates. The stoichiometry and thermal stability of the adducts Cu(II) and Mn(II) beta-diketonates with TBPO in supercritical CO(2) have also been investigated. The implications of utilizing adduct formation for supercritical fluid extraction (SFE) of divalent transition metals and for on-line coupled SFE/SFC analysis of divalent transition metals are discussed.
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, PO Box 999, MS: K8-93, Richland, WA 99352, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Lin
authors.forename: H
authors.initials: H
authors.lastname: Wu
authors.forename: C M
authors.initials: CM
authors.lastname: Wai
authors.forename: N G
authors.initials: NG
authors.lastname: Smart