A rapid, simple spectrophotometric method for simultaneous detection of nitrate and nitrite.
Numerous methods are available for measurement of nitrate (NO(-)(3)). However, these assays can either be time consuming or require specialized equipment (e.g., nitrate reductase, chemiluminescent detector). We have developed a method for simultaneous evaluation of nitrate and nitrite concentrations in a microtiter plate format. The principle of this assay is reduction of nitrate by vanadium(III) combined with detection by the acidic Griess reaction. This assay is sensitive to 0.5 microM NO(-)(3) and is useful in a variety of fluids including cell culture media, serum, and plasma. S-Nitrosothiols and L-arginine derivatives were found to be potential interfering agents. However, these compounds are generally minor constituents of biological fluids relative to the concentration of nitrate/nitrite. This report introduces a new, convenient assay for the stable oxidation products of nitrogen oxide chemistry in biological samples.
Miranda
K M
KM
Radiation Biology Branch, National Cancer Institute, National Institutes of Health, Building 10, Room B3-B69, Bethesda, Maryland 20892, USA. kmiranda@box-k.nih.gov
Espey
M G
MG
Wink
D A
DA
D005029:Ethylenediamines; D016166:Free Radical Scavengers; D007700:Kinetics; D008163:Luminescent Measurements; D009566:Nitrates / Q000097:blood*; D009573:Nitrites / Q000097:blood*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013424:Sulfanilamides; D013696:Temperature; D014639:Vanadium / Q000494:pharmacology
D005029:Ethylenediamines; D016166:Free Radical Scavengers; C095000:Griess reagent; D009566:Nitrates; D009573:Nitrites; D013424:Sulfanilamides; D014639:Vanadium