title: Nitric oxide in biological fluids: analysis of nitrite and nitrate by high-performance ion chromatography.
abstract: The analysis of nitric oxide-derived nitrite and nitrate ions in biological fluids represents a proven strategy for determining nitric oxide participation in a diverse range of physiological and pathophysiological processes in vivo. In this article we describe a versatile method for the simultaneous measurement of NO2- and NO3- anions in both plasma and isolated tumour models based on anion-exchange chromatography with spectrophotometric detection (214 nm). This method compares well with the capillary electrophoresis technique, exhibiting an equivalent sensitivity for NO2-/NO3- anions and short run-times, i.e. not greater than 4 min. Comparisons are also made with two alternative but less satisfactory methods which employ ion-exchange or reversed-phase ion-pair chromatography with conductimetric as well as spectrophotometric detection. Technical problems associated with each method, particularly those arising from nitrate contamination, have been addressed.
authors.affiliation: Cancer Research Campaign Gray Laboratory, Mount Vernon Hospital, Northwood, Middlesex, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: Everett
authors.forename: M F
authors.initials: MF
authors.lastname: Dennis
authors.forename: G M
authors.initials: GM
authors.lastname: Tozer
authors.forename: V E
authors.initials: VE
authors.lastname: Prise
authors.forename: P
authors.initials: P
authors.lastname: Wardman
authors.forename: M R
authors.initials: MR
authors.lastname: Stratford
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007477:Ions; D051379:Mice; D009374:Neoplasms, Experimental / Q000737:chemistry*; D009566:Nitrates / Q000032:analysis; D009569:Nitric Oxide / Q000032:analysis* / Q000097:blood; D009573:Nitrites / Q000032:analysis; D051381:Rats; D015203:Reproducibility of Results; D014462:Ultrafiltration
chemical_list: D007477:Ions; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide