Determination of Nitrate and Nitrite Content of Dietary Supplements Using Ion Chromatography

Nitrate, a compound of low toxicity, when ingested orally, is absorbed from the gastrointestinal tract in its free form. About 20-28% of this is then secreted into saliva and only 4-8% of the ingested nitrate is converted into nitrite by nitrate reducing bacteria. The resulting nitrite is then further reduced to nitric oxide by the same bacteria [1-3]. Many studies have related the beneficial effect of nitrate, nitrite and nitric oxide consumption to cardiovascular health, glucose and calcium regulation, muscle contractility [4,5], mitochondrial bio-synthesis and respiration [6-12], and regulation of blood flow [6,13-15]. Hemodynamic effects [16-18] in the form of increasing exercise performance and as an energy booster have also been reported [5,19,20]. The role of bioactive nitric oxide has recently being evaluated in the form of single dosage [6] or chronic use [21,22]. Its use is independent from the factors such as health status, age and fitness [23,24].