title: Determination of Inorganic Anions in Seawater Samples by Ion Chromatography with Ultraviolet Detection Using Monolithic Octadecylsilyl Columns Coated with Dodecylammonium Cation.
abstract: A fast and sensitive ion chromatographic method for the simultaneous determinations of six inorganic anions [iodate (IO3-), bromate (BrO3-), bromide (Br-), nitrite (NO2-), nitrate (NO3-), and iodide (I-)] in seawater is described using dodecylammonium (DA+)-coated monolithic octadecylsilyl (ODS) columns, a concentrated aqueous NaCl mobile phase containing dodecylammonium chloride (DAC), and a UV detector. The DA+-coated monolithic ODS columns show greater retention for iodate and weaker retention for iodide, compared to dilauryldimethylammonium (DDA+)-coated monolithic ODS columns. Six anions were determined within 12 min with baseline separation without interferences by matrix ions, such as Cl-and SO42-, in seawater, compared to a DA+-coated particulate ODS column (it took 25 min per sample) obtained previously. The detection limits (DLs) were comparable to the DA+-coated particulate ODS column: IO3-(7.7 μg L-1), BrO3-(20), Br-(88), NO2-(0.9), NO3-(1.9), and I-(0.9) with a 100-μL sample injection. A larger sample volume injection lowered the DLs of IO3-, BrO3-, and I-. The good performance was maintained for ca. 2 years examined. The robust IC system developed in the present work was successfully applied to real seawater samples without sample dilution in the recovery rates of 93 - 104% for all ions.
authors.affiliation: Cluster of Biotechnology and Chemistry Systems, Graduate School of Systems Engineering, Kindai University.
authors.forename: Yuuta
authors.initials: Y
authors.lastname: Horioka
authors.forename: Ryuki
authors.initials: R
authors.lastname: Kusumoto
authors.forename: Kengo
authors.initials: K
authors.lastname: Yamane
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Nomura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hirokawa
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ito