Heat-induced formation of nitrogen oxides in water

Abstract

It was found by the fluorimetric method using 2,3-diaminonaphthalene that moderate heating of water (60-80 • C, for up to 4 h) leads to the fixation of atmospheric nitrogen with the formation of nitrite. The kinetic parameters of this process were determined. The energy of activation of NO − 2 formation was estimated to be 139 kJ/mol. It was found that the amount of nitrite formed depends on the concentration of dissolved oxygen and nitrogen. It was shown by two independent methods (Griess reagent/VCl 3 and 2,3-diaminonaphthalene/nitrate reductase) that heating of water (80 • C, 1 h) results in the formation of nitrate; with the use of the fluorescent probe dihydrorhodamine 123, the generation of nitrogen dioxide (peroxynitrite) was revealed. Nitrite, nitrate, and nitrogen dioxide are formed in water upon heating in approximately equal amounts. A scheme of reactions proceeding with bidistilled water by the action of heat with the formation of nitrogen oxides is proposed.

Light-Emitting Photon-Upconversion Nanoparticles in the Generation of Transdermal Reactive-Oxygen Species

“…Heating at 50ºC by applying the laser or having the presence of upconverting nanocrystals (5 mg/mL) did not induce DHR123 degradation, showing the same fluorescence intensity irrespectively of the exposure time (Figure S4) in agreement with the previous literature24 ; however, the presence of nanoparticles and heating simultaneously promoted DHR123 oxidation (Figure 4b). This phenomenon could be partially explained by the generation of reactive nitrogen species after heating water under the presence of DHR123, as previously reported25 . This reaction could be potentially catalyzed by the presence of the lanthanide nanocrystals.…”

“…This phenomenon could be partially explained by the generation of reactive-nitrogen species after the water was heated in the presence of DHR123, as previously reported. 25 This reaction could potentially be catalyzed by the presence of the lanthanide nanocrystals. Upconversion-nanoparticle irradiation at 980 nm induced free-radical generation 1.2 times greater than that induced by the heating of the nanoparticles alone.…”

DNA recovery after sequential processing of latent fingerprints on copy paper

“…This study did not determine whether decreases in DNA yield and STR profile quality were due to DNA loss resulting from immersion of the samples during latent fingerprint development; DNA degradation resulting from exposure to high heat, high humidity, incompatible pH, or deleterious chemicals; or a combination of these factors. Heat induces DNA degradation through a variety of mechanisms that can lead to strand breakage [ 34 ], including hydrolysis [ 35 , 36 ], deamination [ 37 , 38 ], depurination [ 39 ], depyrimidination [ 40 ], and oxidation [ 41 , 42 , 43 ]. Degradation rates resulting from these mechanisms increase as temperature and incubation times increase and pH decreases [ 44 ].…”

“…Latent fingerprints treated sequentially with DFO/laser, ninhydrin, and PD were compared with the untreated latent fingerprints using the aforementioned metrics (Figure 2 mechanisms that can lead to strand breakage [34], including hydrolysis [35,36], deamination [37,38], depurination [39], depyrimidination [40], and oxidation [41][42][43]. Degradation rates resulting from these mechanisms increase as temperature and incubation times increase and pH decreases [44].…”

Nitric oxide formation in the metabolism of nitrates in the oral cavity

“…The highest level of nitrates is contained in groundwater that is in well water, containing about 20 mg/l of nitrate. People living in rural areas consume drinking water containing 20-80 mg/l of nitrates [3].…”