Agents Containing Metals

Table 7. Metal-Containing Industrial Antimicrobial Agents...

Potassium heptafluorotantalate, K2TaF7, or as it is called by its commercial name K-salt, is a starting material for tantalum metal production. K-salt is produced by adding potassium fluoride, KF, or potassium chloride, KC1, to a tantalum strip solution that results from a liquid-liquid extraction process. In order to prevent hydrolysis and co-precipitation of potassium oxyfluoro-tantalate, a small excess of HF is added to the solution [24]. Another way to avoid the possible formation and co-precipitation of oxyfluoride phases is to use potassium hydrofluoride, KHF2, as a potassium-containing agent. The yield of the precipitation depends mostly on the concentration of the potassium-containing salt and is independent of the HF concentration [535]. 

Elimination of nitrosating agents in formulations (e.g. soditim nitrite as corrosion inhibitor for metal containers) use of plastic-lined containers. 

Strong reducing agents such as sulfur dioxide, sodium bisulfite, sodium metabisulfite, and ferrous sulfate are used in the iron and steel finishing sites to reduce hexavalent chromium to the triva-lent form, which allows the metal to be removed from solution by chemical precipitation.21 23 Metal-containing wastewaters may also be treated by chemical precipitation or ion-exchange. 

Bengtsson et al. [671] found that the high background adsorption of solutions of trace metals containing up to 400 mg/1 can be easily minimised by addition of 2% v/v nitric acid. Of the several agents added in an attempt to eliminate the decrease in sensitivity caused by the salt and the variability in sensitivity between graphite tubes, only lanthanum added at 1 g/1 was effective for both lead and cadmium. 

Inorganic or metal-containing medicinal compounds may contain either (a) chemical elements essential to life forms—iron salts used in the treatment of anemia—or (b) nonessential/toxic elements that carry out specific medicinal purposes—platinum-containing compounds as antitumor agents or technetium... 

There are several routes for nitrosamine contamination in pesticides use of contaminated chemicals during synthesis, side reactions, use of nitrite as a preservative and corrosion inhibitor of metal containers and by reactions with environmental nitrosating agents. Over 300 formulations were shown to be contaminated with nitrosamines however, the main contamination was confined to 2,6-dinitroaniline herbicides, dimethylamino salts of phenoxyalkanoic acid herbicide, diethanolamine and triethanolamine salts of acid... 

Also, some distillate fuel stabilizers contain metal chelating agents. The purpose of this is to help prevent the metal-catalyzed oxidation of fuel components. However, if a distillate fuel containing a chelating agent is stored in a tank or transferred through lines which are rusted, the stabilizer may act to chelate iron. As a result of this, the fuel containing the stabilizer appears dark. 

Priming with "Nitramon"and Nitramex 3 primers is described m Ref 50, p 196-98. Since they are packed in metal containers, there is a potential hazard in loading them into a borehole following dynamite or other conventional expls. They are intended only for charges of blasting agents "under most conditions. They are waterproof... 

---