title: Speciation of cationic selenium compounds in Brassica juncea leaves by strong cation-exchange chromatography with inductively coupled plasma mass spectrometry.
abstract: Strong cation-exchange chromatography (SCX-HPLC) was used in conjunction with inductively coupled plasma mass spectrometry (ICP-MS) to investigate cationic selenium species present in leaf extract of wild-type Brassica juncea supplemented with selenite. Total amount of Se accumulated by the leaves was found to be 352 microg g(-1). Cation-exchange solid-phase extraction (SCX-SPE) was used to pre-concentrate the cationic species present in the leaf extract. Methylselenomethionine (MeSeMet) and dimethylselenoniumproprionate (DMSeP) were synthesized and characterized by electrospray quadrupole time-of-flight MS (ESI-QTOF-MS). Laboratory synthesized and commercially available standards were used in chromatographic studies to identify the Se species in the leaf extract through retention time comparisons and standard addition method. Major cationic selenium species identified in the present study were MeSeMet and methylselenocysteine (MeSeCys) while selenomethionine (SeMet) was found in minor quantities.
authors.affiliation: Department of Chemistry, University of Cincinnati, OH 45221-0172, USA.
authors.forename: Santha V Ketavarapu
authors.initials: SV
authors.lastname: Yathavakilla
authors.forename: Monika
authors.initials: M
authors.lastname: Shah
authors.forename: Sandra
authors.initials: S
authors.lastname: Mounicou
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Caruso
mesh_terms: D005591:Chemical Fractionation / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods*; D009149:Mustard Plant / Q000737:chemistry* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry*; D012643:Selenium / Q000378:metabolism; D018036:Selenium Compounds / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D018036:Selenium Compounds; D012643:Selenium