title: Selective determination method for measurement of nitrite and nitrate in water samples using high-performance liquid chromatography with post-column photochemical reaction and chemiluminescence detection.
abstract: A simple, sensitive and selective method for the simultaneous determination of nitrite and nitrate in water samples has been developed. The method is based on ion-exchange separation, online photochemical reaction, and luminol chemiluminescence detection. The separation of nitrite and nitrate was achieved using an anion-exchange column with a 20mM borate buffer (pH 10.0). After the separation, these ions were converted to peroxynitrite by online UV irradiation using a low-pressure mercury lamp and then mixed with a luminol solution prepared with carbonate buffer (pH 10.0). The calibration graphs of the nitrite and nitrate were linear in the range from 2.0 x 10(-9) to 2.5 x 10(-6)M and 2.0 x 10(-8) to 2.5 x 10(-5)M, respectively. Since the sensitivity of nitrite was about 10 times higher than that of nitrate, the simultaneous determination of nitrite and nitrate in the water samples could be efficiently achieved. This method was successfully applied to various water samples--river water, pond water, rain water, commercial mineral water, and tap water--with only filtration and dilution steps.
authors.affiliation: Department of Earth and Environmental Science, Faculty of Science, Kagoshima University, Korimoto, Kagoshima, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kodamatani
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yamazaki
authors.forename: Keiitsu
authors.initials: K
authors.lastname: Saito
authors.forename: Takashi
authors.initials: T
authors.lastname: Tomiyasu
authors.forename: Yu
authors.initials: Y
authors.lastname: Komatsu
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods*; D008165:Luminol / Q000737:chemistry; D009566:Nitrates / Q000032:analysis*; D009573:Nitrites / Q000032:analysis*; D030421:Peroxynitrous Acid / Q000737:chemistry; D055668:Photochemical Processes; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry*
chemical_list: D009566:Nitrates; D009573:Nitrites; D014867:Water; D030421:Peroxynitrous Acid; D008165:Luminol