title: Anion separations for liquid chromatography using propylpyridinium silica as the stationary phase.
abstract: This work describes the characterization and potential applications of a silica-based anion-exchange phase prepared by a two-step modification process that incorporates a propylpyridinium group. The effects of pH and eluent concentration on anion separation were examined using 150 mm × 3.9 mm HPLC columns packed with the new phase. The mobile phase pH values ranged from 3.8 to 6.6 using phthalic acid/Tris solutions. The best separation was achieved using 2.5 mmol L(-1) phthalate/2.4 mmol L(-1) Tris solution at pH 4.2 as mobile phase with non-suppressed conductivity detection. The new stationary phase was used for the separation of some inorganic and organic anions showing good resolution. The stability of the silica-based anion exchange phase was also evaluated. Analytical curves, for concentrations ranging from 0.25 to 10 mg L(-1) for the inorganic anions chloride, nitrite, bromide and nitrate, showed good linear correlations (r>0.998). The method was tested with certified rainwater samples. The measured and certified values were in good agreement, indicating that the new phase holds significant promise for the analysis of these anions in environmental samples.
authors.affiliation: CDTN/CNEN - Center for Nuclear Technology Development, Brazilian Nuclear Energy Commission, POB 941, 30123-970 Belo Horizonte, MG, Brazil.
authors.forename: Lúcia M L A
authors.initials: LM
authors.lastname: Auler
authors.forename: César R
authors.initials: CR
authors.lastname: Silva
authors.forename: Carla B G
authors.initials: CB
authors.lastname: Bottoli
authors.forename: Carol H
authors.initials: CH
authors.lastname: Collins
mesh_terms: D000838:Anions / Q000032:analysis / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002852:Chromatography, Ion Exchange / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D011726:Pyridinium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012822:Silicon Dioxide / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000838:Anions; D011726:Pyridinium Compounds; D012822:Silicon Dioxide