title: CE-ESI-MS analysis of singly charged inorganic and organic anions using a dicationic reagent as a complexing agent.
abstract: A dicationic ion-pairing reagent, N,N'-dibutyl 1,1'-pentylenedipyrrolidinium, was used to form complexes with singly charged anions for their subsequent analysis by CE-ESI-MS in positive ion mode. This methodology offers the advantages of greater versatility and sensitivity relative to direct detection of the anions in negative ion mode, and it can be realized by a number of possible complexation strategies, including pre-column, on-column, and post-column modes. Four model anions, perfluorooctanoate, benzenesulfonate (BZSN), monochloroacetate (MCA), and trifluoromethanesulfonimide were amenable to complexation with the dicationic reagent, yielding singly charged cations with greater m/z. By optimizing various parameters, including the CE separation buffer composition and pH, the concentration of the dicationic reagent, the mode of complexation, the nebulizing gas pressure, and the sheath liquid composition, it was possible to develop a robust CE-ESI-MS method appropriate for the analysis of anions in a tap water sample. By this method, LODs were found to be 20.9 and 1.31 ng/mL for MCA and BZSN, respectively.
authors.affiliation: Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Lin
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Gerardi
authors.forename: Zachary S
authors.initials: ZS
authors.lastname: Breitbach
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Armstrong
authors.forename: Christa L
authors.initials: CL
authors.lastname: Colyer
mesh_terms: D000085:Acetates / Q000032:analysis*; D000838:Anions / Q000032:analysis*; D001557:Benzenesulfonates / Q000032:analysis*; D002210:Caprylates / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005466:Fluorocarbons / Q000032:analysis*; D007094:Imides / Q000032:analysis; D007202:Indicators and Reagents; D008698:Mesylates / Q000032:analysis*; D011758:Pyrroles / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis; D014881:Water Supply / Q000032:analysis
chemical_list: D000085:Acetates; D000838:Anions; D001557:Benzenesulfonates; D002210:Caprylates; D005466:Fluorocarbons; D007094:Imides; D007202:Indicators and Reagents; D008698:Mesylates; C547199:N,N-dibutyl 1,1-pentylenedipyrrolidinium; D011758:Pyrroles; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; C006972:chloroacetic acid; C032365:benzenesulfonic acid; C023036:perfluorooctanoic acid; C012077:trifluoromethanesulfonic acid