title: High-resolution capillary electrophoresis of nitrite and nitrate in biological samples.
abstract: Nitrite and nitrate are widely used reporters of endogenous nitric oxide (NO) and nitric oxide synthase (NOS) activity, which are crucial for a broad spectrum of physiological and pathophysiological pathways. Because of the great variety in spatial expression and activity of NOS in animal tissues, a high-resolution analysis of nitrite/nitrate concentrations in very small biological samples, such as individual cells or homogeneous cell clusters, is required. A high-performance capillary zone electrophoresis (CZE) system, which includes a PrinCE-476 computerized capillary electrophoresis and Crystal-1000 conductivity detector, was optimized to analyze nitrite/nitrate concentrations in submicroliter samples of mammalian neuronal tissues and large individual cells of invertebrates. Solid-phase microextraction (SPME) and Isotachophoretic stacking (ITS) were used. The method is highly reproducible and yield excellent limits of detection (LODs): 8.9 nM (0.41 ppb) and 3.54 nM (0.22 ppb) for nitrite and nitrate, respectively, relative to undiluted samples.
authors.affiliation: The Whitney Laboratory, University of Florida, St. Augustine, USA.
authors.forename: Dmitri Y
authors.initials: DY
authors.lastname: Boudko
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods; D009566:Nitrates / Q000032:analysis*; D009569:Nitric Oxide / Q000032:analysis*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009573:Nitrites / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase