title: High-throughput nitric oxide assay in biological fluids using microchip capillary electrophoresis.
abstract: In order to develop a high-throughput screening method for the nitrogen monoxide metabolites, nitrite and nitrate, in biological fluids, we have investigated the simultaneous determination of these metabolites using microchip capillary electrophoresis (MCE). In this study, the control of applied voltage to obtain higher sensitivity by increasing the sample injection volume was investigated. Also, the improvement of reproducibility by correcting the injection volume using the internal standard was investigated. By increasing the sample volume, the limits of detection achieved for nitrite and nitrate were 24 and 12 microM, respectively. Because we used a 10-fold diluted sample when detecting nitrite and nitrate in human serum, it was necessary to increase the sensitivity by a factor of 10-50. The run-to-run and day-to-day relative standard deviations achieved were improved to less than 10% by using an internal standard to correct the injection volume. Moreover, we obtained successful separation of nitrite and nitrate in spiked human serum within 6.5 s under optimum analytical conditions. As a result, although it is necessary to obtain greater sensitivity, it was concluded that determination of the amount of NO metabolites in biological fluids using MCE is possible.
authors.affiliation: Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science and Technology, (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Miyado
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Hidenori
authors.initials: H
authors.lastname: Nagai
authors.forename: Sahori
authors.initials: S
authors.lastname: Takeda
authors.forename: Keiitsu
authors.initials: K
authors.lastname: Saito
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fukushi
authors.forename: Yasukazu
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Wakida
authors.forename: Etsuo
authors.initials: E
authors.lastname: Niki
mesh_terms: D002138:Calibration; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009569:Nitric Oxide / Q000097:blood*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D009569:Nitric Oxide