Preservative inorganic salt

The burning process leaves very little solid remains only ash, made up of inorganic salts that rarely make up more than a few percent of the total mass of wood. When wood bums with a restricted supply of air, however, and there is insufficient oxygen to combine with all the carbon in the wood, the remains are made up of charcoal, a very porous and impure form of carbon. Charcoal is extremely stable it does not decay, nor is it altered by most microorganisms, and it may be preserved for very long periods of time charcoal often also preserves the morphology of the burned wood. Because of its stability, charcoal residues are often found in archaeological sites where wood was either used as fuel or otherwise burned. 

During sampling cruises 3-5, 20 L of sample from the ultrafilter was preserved with chloroform, shipped back to an analytical laboratory, and vacuum-evaporated to 500 mL before being passed through a 500-mL column of XAD-8 resin (27). This revised procedure should have increased the recovery of DOM because of a 10-fold increase in the resin water ratio. In addition, hydrophilic organic solutes that did not adsorb on the XAD-8 resin were isolated by a vacuum-evaporation procedure whereby water is distilled from acetic acid and inorganic salts precipitate in the acetic acid (28). Recoveries of DOC by the two procedures are presented in Table IV. 

In salt solutions or mixtures of miscible liquids, the coalescence of tiny primary gas bubbles is suppressed significantly the higher the concentration of the solution, the better the size of the primary gas bubbles is preserved. The stable bubble size in this case is 0.2-0.5 mm, an order of magnitude smaller than in pure liquids. As a result of coalescence suppression, the enhancement factor of physical sorption m = (kLa)sol/(kLa)soly rises to 7 or 8, which has been confirmed by measurements of kLaL as a function of the concentration of various inorganic salts (both strong and weak electrolytes) as well as normal aliphatic alcohols (methanol to octanol) (Zlokarnik, 1980,1985). 

Inorganic salts are employed in preservative treatment where the wood will not be in contact with the ground or water, such as for indoor use or where the treated wood requires painting. They are also satisfactory for outdoor use in relatively dry regions. 

RIA techniques generate great amounts of radioactive liquid wastes whose composition depends on the specific assays that are carried out in each laboratory. Liquid wastes from RIA techniques are usually composed of different types of proteins (some of them radioactively labelled), preservative solutions, several low-molecular-weight organic compounds, and inorganic salts— all in aqueous solutions. These wastes are classified as low and medium radioactive, but they are also potentially infectious since they can contain pathogens from patient s blood [4]. Sometimes, the infectious risks of these wastes can be much more dangerous than the risks associated with radioactivity. 

Inorganic Salts. A number of the metal salts have fungicidal activity and are used to formulate commercial wood preservatives. The principal metal salts used are compounds of arsenic, chromium, copper, and zinc. In order to provide the desired fungicidal activity, leach resistance, and low corrosivity, combinations of these compounds are used. All of the formulations discussed later are waterborne solutions. Only a brief description of these preservative systems will be presented here more detailed presentations can be found elsewhere (3). 

Inorganic Salt Preservatives. Inorganic compounds used to formulate wood preservatives are normally water soluble. As a result, the salts deposited in the wood are susceptible to leaching unless they are transformed to insoluble compounds or are chemically fixed to the wood substrate. Indeed, such conversions do occur as a result of interactions between some of the salts and the wood substrate. Both single element and multicomponent reactions are involved in the fixation mechanisms copper and chromium are the most reactive of the possible components. 

Organic Preservatives. In contrast to inorganic salts, the organic preservatives are much less reactive with wood. This is particularly true for the standard preservative—creosote and pentachlo-rophenol (penta). Nevertheless, some of the other minor-use or new preservatives are more reactive and undergo various reactions with... 

Protective effects of chromic acid and ferric chloride treatments on surface degradation also were observed on radial surfaces. The preservation of both simple and bordered pits in woods treated by these inorganic salts was observed. At a 10% chromic acid treatment concentration, the structure of the pits retained most of the original shape after 1000 h of UV irradiation. The diagonal microchecks passing through the bordered pits in radial walls of tracheids, however, can still be observed (Figure 30). 

Povidone is compatible in solution with a wide range of inorganic salts, natural and synthetic resins, and other chemicals. It forms molecular adducts in solution with sulfathiazole, sodium salicylate, salicylic acid, phenobarbital, tannin, and other compounds see Section 18. The efficacy of some preservatives, e.g. thimerosal, may be adversely affected by the formation of complexes with povidone. 

Supercritical extracts therefore have a unique and concentrated spectrum of lipophilic ingredients. They have the general advantage of being free of solvents, inorganic salts and heavy metals. They are practically sterile [10] and they need no preservatives since they do not provide a base for germ growth due to the absence of water, proteins and polysaccharides. All this allows a safe application and simple declaration. 

The test identifies the substance to be examined as either a salt of mercury, Hg2 + or Hg + or a substance containing covalently bound mercury. At the present, reference to mercury is made in only two monographs. One is an inorganic salt mercuric chloride, HgCl2, which has antibacterial action through precipitation proteins and thimerosal (Figure 3.24.1), which likewise is an antiseptic but also a preservative in pharmaceutical product. The use... 

Production of animal glue is considered as environmentally friendly , since it involves conversion of unpleasant waste into useful products, but economic operation depends on satisfactory disposal of residues some of these are used as slow-release nitrogenous fertilizers. The mineral residue from bone glue production ( bone meal ) by thermal methods is used as a phosphate supplement in animal feed and fertilizers it is also calcined at 1000-1200 °C to produce calcined bone, used in the manufacture of bone china to provide strength and translucency. Animal glues and technical gelatins contain added preservatives and a proportion of non-protein materials, usually mucopolysaccharides and soluble inorganic salts. These impurities differ with the source of raw material. 

Because a great variety of sources contribute materials to the tropospheric aerosol, it represents a complex mixture of marry substances that additionally depends on the size of the particles. Source characteristics are preserved only in the vicinity of somces. The mixtirre may be divided into three fractiorts water-solirble inorganic salts (electrolytes), water-irrsoluble minerals, and organic compoimds, both soluble in water and insoluble. Table II shows the chemical composition of two boimdary layer aerosols that are typical of marine and of rural continental air. 

NR can also be exported as concentrated latex. Fresh field latex consists of 30-40% dry rubber content (DRC), the other 60-70% being mainly water-containing non-rubber substances. The non-rubber components, e.g. proteins, carbohydrates, lipids and inorganic salts, vary according to clones, season and age of rubber tree. The latex collected from the plantation is preserved with ammonia (NH3) and then undergoes continuous centrifugation to produce the... 

Water-borne solutions of inorganic salts are also used. These have the advantages over the oils of greater ease of penetration and freedom from fire hazards and odor. The disadvantage is that they cause swelling and some react with metal. The primary preservative used is chromated zinc chloride. Other typical salts used are as follows ... 

The necessity of monitoring the levels of preservatives (waterborne inorganic salts as well as organic solvents and creosote) in treated timber arises from the fact that such timber is supposed to be treated to specified levels or retentions (kg preservative salt m wood), depending on the biological hazard to... 

For the size exclusion chromatography of proteins on silica-hased diol packings, it is generally recommended to use fully aqueous mobile phases with a salt concentration between 0.1 and 0.3 M. In general, a phosphate buffer around pH 7 is used as the mobile phase. Under these circumstances, the tertiary structure of most proteins is preserved without difficulty and the interaction of proteins with each other is minimized. However, other inorganic buffers or combinations of buffers with organic solvents can be used without difficulties for special applications. 

Similar to inorganic acids, the reaction of carboxylic acids and bases produces carboxylic acid salts. Several of these salts are commonly used in foods and beverages as preservatives. The most common are salts from benzoic, propionic, and sorbic acids. The salts of these acids have names ending with ate, and can often be found in the list of ingredients of baked goods and fruit drinks. Several common preservatives are shown in Figure 15.11. 

---