title: Observation of Na(+)-bound oligomers of quercetin in the gas phase.
abstract: While developing a liquid chromatography/tandem mass spectrometry method for the analysis of the flavonoid quercitin, it was observed that quercetin (3,3',4',5,7-pentahydroxyflavone) exhibited clustering in both the positive and negative ion mode. Two series of positive ion clusters were observed; the first series corresponds to singly charged [2M + Na](+) at m/z 627.2 to [13M + Na](+) at m/z 3947.5, while the second series corresponds to doubly charged [7M + 2Na](2+) at m/z 1080.4 to [25M + 2Na](2+) at m/z 3798.5. In the negative ion mode, the behavior of quercetin parallels that of apigenin (4',5,7-trihydroxyflavone) in that [M + NO(3)](-), [2M + NO(3)](-), and [3M + NO(3)](-) were observed at m/z 364.1, 666.0, and 968.9, respectively; in addition, quercitin clusters with chloride ions ([2M + Cl](-) at m/z 638.9 and [3M + Cl](-) at m/z 940. 9) were observed. The results of tandem mass spectrometric examination of several cluster ions are reported.
authors: Water Quality Centre, Trent University, Peterborough ON K9J 7B8, Canada.
authors: T R
authors: TR
authors: Croley
authors: R J
authors: RJ
authors: Hughes
authors: C
authors: C
authors: Hao
authors: C D
authors: CD
authors: Metcalfe
authors: R E
authors: RE
authors: March
mesh_terms: D005740:Gases; D007477:Ions; D046911:Macromolecular Substances; D013058:Mass Spectrometry / Q000379:methods; D011794:Quercetin / Q000032:analysis / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry*
chemical_list: D005740:Gases; D007477:Ions; D046911:Macromolecular Substances; D011794:Quercetin; D012964:Sodium