title: Ion chromatography for determination of nitrite and nitrate in seawater using monolithic ODS columns.
abstract: A fast and highly sensitive ion chromatographic method using monolithic ODS columns was developed for the determination of nitrite (NO2-) and nitrate (NO3-) in seawater. Two monolithic ODS columns (50 mm x 4.6 mm i.d. + 100 mm x 4.6 mm i.d.) connected in series were coated and equilibrated with 5 mM cetyltrimethylammonium chloride (CTAC) aqueous solution. The column efficiency with 0.5 M NaCl as the mobile phase did not decrease in spite of the increase in flow rate of the mobile phase. Thus, good chromatograms were obtained within 3 minutes for NO2- and NO3 in artificial seawater without interferences by coexisting ions. The detection limit (S/N = 3) with UV detection at 225 nm was 0.8 and 1.6 microg/L for NO2- and NO3-, respectively. The characteristics of the monolithic CTA(+)-coated ODS columns were discussed. The present method was successfully applied to the fast and sensitive determination of NO2- and NO3- in real seawater samples.
authors.affiliation: Department of Biotechnology and Chemistry, School of Engineering, Kinki University, 1 Umenobe, Takaya, Higashi-Hiroshima 739-2116, Japan. itok@hiro.kindai.ac.jp
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ito
authors.forename: Yohichi
authors.initials: Y
authors.lastname: Takayama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Makabe
authors.forename: Ryo
authors.initials: R
authors.lastname: Mitsui
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hirokawa
mesh_terms: D002852:Chromatography, Ion Exchange / Q000295:instrumentation* / Q000379:methods; D009566:Nitrates / Q000032:analysis*; D009573:Nitrites / Q000032:analysis*; D016062:Porosity; D012623:Seawater / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009566:Nitrates; D009573:Nitrites