Ion chromatography is a new analytical technique in which the ions to be analyzed are separated on a special pellicular ion-exchange column. Once separated, the effluent from the separating column passes into a second ion-exchange column, which removes the eluent or buffer ions from the moving phase without removing the sample ions, which are detected and measured by electrical conductivity on ...

Germfree and conventional-flora Sprague-Dawley rats were fed sodium nitrate or sodium nitrite in their drinking water (1,000 microgram/ml), and various organs, tissues, and sections of the intestinal tract were assayed for nitrate (NO3-) and nitrite (NO2-) by a spectrophotometric method. When fed NO3-, germfree rats had chemically detectable levels of NO3- (only) in the stomach, small intestine...

The chemical basis for commercial production and purification of nitrous oxide is outlined and discussed. Nitric oxide is the most likely toxic contaminant but the concentration in the effluent gas from a cylinder diminishes rapidly due to fractionation. Nitric oxide reacts with oxygen but the velocity of the reaction is influenced by concentration and is very slow at concentrations below about...

Various enzymic systems, such as nitrite reductase, sulfite reductase and glutathione reductase, have been proposed for, or suspected to be involved in, the reduction of selenite in bacteria. As alphaproteobacteria have been shown to be highly tolerant to transition metal oxyanions, it seemed interesting to investigate the hypothetical involvement of these different enzymes in the reduction of ...

Nitrite is widespread in the environment, and frequently used as an additive to extend shelf life of meat products. However, excess intake nitrite can be harmful human health. Hence, it very important know control content foodstuffs. In this work, by means self-assembly induced solvent evaporation, we amphiphilic PEO-b-PS diblock copolymers resol cobalt nitrate a template synthesize ordered mes...

The capacity of natural zeolites to absorb anionic pollutants from water is limited. This limitation can be overcome by modifying the surface of the minerals with organic cations. In this research, natural zeolite, Analcime was used for removing the nitrate and nitrite impurities from aqueous solutions. The surface of the zeolite was modified by tetramethylammonium and tetraethylammonium ions t...

Resonance Raman spectroscopy at ambient temperature and 77 K has been used to probe the structures of the copper sites in Achromobacter cycloclastes nitrite reductase. This enzyme contains three copper ions per protein molecule and has two principal electronic absorption bands with lambda max values of 458 and 585 nm. Comparisons between the resonance Raman spectra of nitrite reductase and blue...