Hydrogen peroxide is a potent oxidizer. Its aqueous solution is suitable for cleaning surfaces, food, etc. However, paying attention to the solution's concentration is crucial because solutions containing more hydrogen peroxide than 8% might erode the skin. It has several uses and may also be used as a rocket propellant. Ammonia is ubiquitous throughout nature. It exists in the air, all water, and soil. Ammonia is a colorless and strongly pungent gas. It is an inorganic compound. Ammonia can make the moist red litmus test paper turn blue and appear weakly alkaline. It can be soluble in water, ethanol, and ether. It can be directly synthesized from nitrogen and hydrogen and will decompose into nitrogen and hydrogen at high temperatures.

Synergistic effect on lignin

For the disadvantages of the traditional ammonia fiber expansion (AFEX) process, a combined hydrogen peroxide and ammonia fiber expansion (H-AFEX) pretreatment is developed. Results show that both lignin removal and sugar yield are enhanced when applying the H-AFEX pretreatment to corn leaf or energy crop. So far, many combined pretreatments have been developed and reported. However, most of the emerging combined pretreatments are still just process optimization. On the one hand, the mechanism of combined pretreatment remains to be further studied. On the other hand, the synergistic effect of combined pretreatment is often overlooked[1].

To reveal the synergistic effect of hydrogen peroxide and ammonia on lignin, four kinds of ball-milled wood lignins, named UN-L, HP-L, AFEX-L, and H-AFEX-L respectively, were isolated from corn stover of untreated, hydrogen peroxide pretreatment alone, ammonia fiber expansion pretreatment alone and combined hydrogen peroxide and ammonia fiber expansion pretreatment. The results showed that oxidation and ammonolysis were the main chemical reactions during H-AFEX pretreatment. The action site of oxidation was S unit, while that of ammonolysis were ferulate and p-coumarate ester bonds. The synergistic effect of hydrogen peroxide and ammonia strengthened the ammonolysis effect, whereas it weakened the oxidation effect. Ammonia selectively degraded the ester bond, while hydrogen peroxide selectively degraded the resinol structure. The synergistic effect of hydrogen peroxide and ammonia could effectively degrade lignin and greatly reduce its PI to obtain homogeneous lignin fragments.

Retard gastric epithelial restoration in rabbit cultured cell model

In addition, Ammonia (NH3), hydrogen peroxide (H2O2), and monochloramine (NH2Cl) produced by Helicobacter pylori infection might be responsible for mucosal injury. Artificial wounds were made in confluent monolayer gastric epithelial cell sheets by mechanical denudation and changes in the size of the cell-free area were analyzed quantitatively[2]. Cell proliferation was assessed by bromodeoxyuridine staining. In controls, the wound healed within 48 hr. However, mucosal cell repair was inhibited by treatment with NH3, H2O2, and NH2Cl in a dose-dependent manner. These results indicate that NH3, H2O2, and NH2Cl retarded the wound healing, which included epithelial cell migration and proliferation of gastric mucosa. Therefore, it is suggested that NH3, H2O2, and NH2Cl delay the healing process of peptic ulcers.

References

[1] Chao Zhao. “Synergistic effect of hydrogen peroxide and ammonia on lignin.” Industrial Crops and Products 146 (2020): Article 112177.

[2] K Sato. “Ammonia, hydrogen peroxide, and monochloramine retard gastric epithelial restoration in rabbit cultured cell model.” Digestive Diseases and Sciences 44 12 (1999): 2429–34.