Nitric oxide in biological fluids: analysis of nitrite and nitrate by high-performance ion chromatography.
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.
Everett
S A
SA
Cancer Research Campaign Gray Laboratory, Mount Vernon Hospital, Northwood, Middlesex, UK.
Dennis
M F
MF
Tozer
G M
GM
Prise
V E
VE
Wardman
P
P
Stratford
M R
MR
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
D007477:Ions; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide