title: Simultaneous separation of inorganic anions and metal-citrate complexes on a zwitterionic stationary phase with on-column complexation.
abstract: The retention and separation selectivity of inorganic anions and on-column derivatised negatively charged citrate or oxalate metal complexes on reversed-phase stationary phases dynamically coated with N-(dodecyl-N,N-dimethylammonio)undecanoate (DDMAU) has been investigated. The retention mechanism for the metal-citrate complexes was predominantly anion exchange, although the amphoteric/zwitterionic nature of the stationary phase coating undoubtedly also contributed to the unusual separation selectivity shown. A mixture of 10 inorganic anions and metal cations was achieved using a 20 cm monolithic DDMAU modified column and a 1 mM citrate eluent, pH 4.0, flow rate equal to 0.8 mL/min. Selectivity was found to be strongly pH dependent, allowing additional scope for manipulation of solute retention, and thus application to complex samples. This is illustrated with the analysis of an acidic mine drainage sample with a range of inorganic anions and transition metal cations, varying significantly in their concentrations levels.
authors.affiliation: National Centre for Sensor Research, School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
authors.forename: Ekaterina P
authors.initials: EP
authors.lastname: Nesterenko
authors.forename: Pavel N
authors.initials: PN
authors.lastname: Nesterenko
authors.forename: Brett
authors.initials: B
authors.lastname: Paull
mesh_terms: D000838:Anions / Q000737:chemistry / Q000302:isolation & purification; D002412:Cations / Q000737:chemistry / Q000302:isolation & purification; D002852:Chromatography, Ion Exchange / Q000379:methods*; D019343:Citric Acid / Q000737:chemistry*; D005227:Fatty Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008672:Metals, Alkali / Q000737:chemistry / Q000302:isolation & purification*; D008673:Metals, Alkaline Earth / Q000737:chemistry / Q000302:isolation & purification*; D010070:Oxalates / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D028561:Transition Elements / Q000737:chemistry / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D000838:Anions; D002412:Cations; D005227:Fatty Acids; D008672:Metals, Alkali; D008673:Metals, Alkaline Earth; D010070:Oxalates; D000644:Quaternary Ammonium Compounds; D028561:Transition Elements; D014874:Water Pollutants, Chemical; D019343:Citric Acid; C093274:(N-dodecyl-N,N-dimethylammonio)undecanoic acid