Hydrolysis,alkaline

Hydrolysis alkaline chemical hydrolysis t,A > 365 d (Schnoor McAvoy 1981 quoted, Schnoor 1992). Biodegradation aerobic t,/2 = 14 d for 0.06 pg/mL to degrade in pond water and t,/2 > 28 d in pond sediment both at 10-20°C (Roberts 1974 quoted, Muir 1991). 

Hydrolysis alkaline hydrolysis rate constant k = 0.182 M s at 25°C in water (Salmi Leimu 1947 quoted, Drossman et al. 1988). 

Hydrolysis alkaline hydrolysis rate constant at 25°C, k = 171 h (Sharma Sharma 1970 quoted, Ellington... 

The principal lipid constituent of the tubercle bacilli was a wax-like substance. Anderson obtained this by chloroform extraction of fat-free bacilli. The preliminary removal of lipids with alcohol and other solvents served to dissolve the free fatty acids, neutral fat and phospha-tides. The crude wax was fractionated with alcohol or acetone. The purified derivative was a white amorphous powder containing 0.41% nitrogen and 0.77% phosphorus. The substance was very resistant to acid hydrolysis. Continuous treatment with acidified alcohol resulted in very slow hydrolysis. Alkaline hydrolysis proceeded very rapidly, with the formation of ether-soluble components together with a water-soluble polysaccharide. 

M. Alborz and K.T. Douglas, Effect of an Aromatic Ester Conjugate Base on ElcB Ester Hydrolysis. Alkaline Hydrolysis of Fluorene-9-Carboxylate Esters, J. Chem. Soc. Perkin Trans. 2, 1982, 331. 

A systematic study of the relative lability of the amino groups in the 2- and 4-positions of pyrimidines toward acid (HC1) hydrolysis, alkaline (NaOH) hydrolysis, and nitrous acid treatment has been made.354 In pyrido[2,3-amino group is exchanged for a hydroxy group by nitrous acid treatment, and after hydrolysis of the 4-amino group, by acid hydrolysis, too, but there is no reaction with alkali. The 4-amino group does not react with nitrous acid, but is hydrolyzed in acidic as well as in alkaline medium. 

Short syntheses of L-fucose analogues have been achieved (3 enzymatic steps) by aldol condensation of DHAP with various a-hydroxyaldehyde derivatives (using L-fuculose phosphate aldolase), followed by phosphate hydrolysis (alkaline phosphatase) and subsequent ketol isomerization (L-fucose isomerase). Selective C-labelling of thymidine in all positions of the 2 -deoxyribose ring has been achieved using an aldolase-catalysed reaction with appropriately C-labelled DHAP/acetaldehyde substrates. The labelled sugar was then converted... 

Besides acid hydrolysis, alkaline hydrolysis is also prevalent, which focuses on the partial separation of the cellulose fibers from the cell wall and an improvement in the physical and chemical characteristics of cellulose, particularly its reactivity to other chemical agents. 

Separation of biomass components is the very important initial step for the upcoming efficient utilization of biomass sources. Several physical and chemical separation methods are currently employed to overcome the recalcitrance of lignocelluloses. These methods include acid hydrolysis, alkaline hydrolysis, ammonia fiber expansion, hot water, organic solvent, and ionic liquid separation technologies. In this section of the chapter, all of the above separation methods are discussed. 

Alkaline baths contain complex compounds of the metal to be plated and are, as their name implies, alkaline. The most common ligand used is cyanide (for the plating of copper, cadmium, gold, silver and zinc, for example) and since it hydrolyses at neutral pH, sodium or potassium hydroxide or excess cyanide is added to the bath to repress this hydrolysis. Alkaline baths absorb carbon dioxide from the atmosphere to form carbonates. When the carbonates precipitate the metal to be plated this can be a serious problem. A general solution, however, is not available. 

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