title: Sequential injection chromatography with post-column reaction/derivatization for the determination of transition metal cations in natural water samples.
abstract: In this work, the applicability of Sequential Injection Chromatography for the determination of transition metals in water is evaluated for the separation of copper(II), zinc(II), and iron(II) cations. Separations were performed using a Dionex IonPAC™ guard column (50mm×2mm i.d., 9 µm). Mobile phase composition and post-column reaction were optimized by modified SIMPLEX method with subsequent study of the concentration of each component. The mobile phase consisted of 2,6-pyridinedicarboxylic acid as analyte-selective compound, sodium sulfate, and formic acid/sodium formate buffer. Post-column addition of 4-(2-pyridylazo)resorcinol was carried out for spectrophotometric detection of the analytes׳ complexes at 530nm. Approaches to achieve higher robustness, baseline stability, and detection sensitivity by on-column stacking of the analytes and initial gradient implementation as well as air-cushion pressure damping for post-column reagent addition were studied. The method allowed the rapid separation of copper(II), zinc(II), and iron(II) within 6.5min including pump refilling and aspiration of sample and 1mmol HNO3 for analyte stacking on the separation column. High sensitivity was achieved applying an injection volume of up to 90µL. A signal repeatability of<2% RSD of peak height was found. Analyte recovery evaluated by spiking of different natural water samples was well suited for routine analysis with sub-micromolar limits of detection.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic. Electronic address: Horstkob@faf.cuni.cz.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Horstkotte
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Jarošová
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Chocholouš
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Sklenářová
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Solich
mesh_terms: D002845:Chromatography / Q000379:methods*; D003300:Copper / Q000032:analysis*; D060766:Drinking Water / Q000032:analysis; D005561:Formates / Q000737:chemistry; D005618:Fresh Water / Q000032:analysis; D007501:Iron / Q000032:analysis*; D008900:Mineral Waters / Q000032:analysis; D010848:Picolinic Acids; D011725:Pyridines / Q000737:chemistry; D012118:Resorcinols / Q000737:chemistry; D013431:Sulfates / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015032:Zinc / Q000032:analysis*
chemical_list: D060766:Drinking Water; D005561:Formates; D008900:Mineral Waters; D010848:Picolinic Acids; D011725:Pyridines; D012118:Resorcinols; D013431:Sulfates; D014874:Water Pollutants, Chemical; C030544:formic acid; C012036:sodium sulfate; D003300:Copper; D007501:Iron; D015032:Zinc; C028398:4-(2-pyridylazo)resorcinol; C004860:dipicolinic acid
keywords: On-column stacking; Post-column reaction; Sequential Injection Chromatography; Spectrophotometric detection; Transition metal cations