title: Biosynthesis of Cd-bound phytochelatins by Phaeodactylum tricornutum and their speciation by size-exclusion chromatography and ion-pair chromatography coupled to ICP-MS.
abstract: Cd-bound phytochelatins (Cd-PCs) have been synthesised by incubation of Phaeodactylum tricornutum cell cultures with Cd and purified by size-exclusion chromatography-UV-Vis. These complexes, which were identified in previous work, have now been used as model substances to develop and optimise ion-pair chromatography (IPC) coupled to inductively coupled plasma-mass spectrometry (ICP-MS) for analysis of Cd-PCs. Subsequent analysis of samples taken from Silene vulgaris plants cultivated under heavy metal stress conditions revealed Cd signals but no Cd-PC signals. By use of isotopically enriched (116)Cd-PCs the sample preparation steps were verified to determine the stability of the analytes. We observed species transformation between Cd-PCs and other unidentified Cd complexes. Consequently, the kinetic and thermodynamic lability of Cd-PCs are decisive factors in their detection.
authors.affiliation: Institute of Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Duesbergweg 10-14, 55099 Mainz, Germany.
authors.forename: Valeria
authors.initials: V
authors.lastname: Loreti
authors.forename: Daniel
authors.initials: D
authors.lastname: Toncelli
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Morelli
authors.forename: Gioacchino
authors.initials: G
authors.lastname: Scarano
authors.forename: Jörg
authors.initials: J
authors.lastname: Bettmer
mesh_terms: D002104:Cadmium / Q000737:chemistry / Q000378:metabolism*; D002457:Cell Extracts; D002850:Chromatography, Gel; D056890:Eukaryota / Q000737:chemistry* / Q000378:metabolism*; D005978:Glutathione / Q000096:biosynthesis* / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D013058:Mass Spectrometry; D054811:Phytochelatins; D029751:Silene / Q000737:chemistry / Q000378:metabolism
chemical_list: D002457:Cell Extracts; D002104:Cadmium; D054811:Phytochelatins; D005978:Glutathione