title: Simultaneous analysis of nitrite, nitrate and the nicotinamide nucleotides by capillary electrophoresis: application to biochemical studies and human extracellular fluids.
abstract: A simple but rapid capillary electrophoresis method was developed for the measurement of nitrite and nitrate in human extracellular fluids and other aqueous solutions. The capabilities of the method were demonstrated by the measurement of endogenous nitrite and nitrate in plasma and serum samples from healthy volunteers, and serum and synovial fluid samples from rheumatoid arthritis patients. Furthermore, this method was used to simultaneously measure nicotinamide adenine dinucleotide, reduced (NADH), nicotinamide adenine dinucleotide (NAD+), nitrite, and nitrate, when studying the nitrite reductase activity of xanthine oxidase. The stability of nitrite was also investigated and it was found that when whole blood was spiked with nitrite and then processed, the nitrite was more stable in the plasma than in the serum. Our findings may help to explain the variations in basal nitrite concentrations reported in the literature.
authors.affiliation: Bone and Joint Research Unit and the Medical Unit, St Bartholomew's and the Royal London School of Medicine and Dentistry, Whitechapel, UK. c.a.boam@mds.qmw.ac.uk
authors.forename: C A
authors.initials: CA
authors.lastname: Davies
authors.forename: D
authors.initials: D
authors.lastname: Perrett
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: B R
authors.initials: BR
authors.lastname: Nielsen
authors.forename: D R
authors.initials: DR
authors.lastname: Blake
authors.forename: P G
authors.initials: PG
authors.lastname: Winyard
mesh_terms: D001826:Body Fluids / Q000737:chemistry*; D004355:Drug Stability; D019075:Electrophoresis, Capillary / Q000379:methods*; D005110:Extracellular Space / Q000737:chemistry*; D006801:Humans; D009243:NAD / Q000032:analysis* / Q000097:blood; D009566:Nitrates / Q000032:analysis* / Q000097:blood; D009572:Nitrite Reductases / Q000378:metabolism; D009573:Nitrites / Q000032:analysis* / Q000097:blood; D013582:Synovial Fluid / Q000737:chemistry; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D009566:Nitrates; D009573:Nitrites; D009243:NAD; D014969:Xanthine Oxidase; D009572:Nitrite Reductases