Strontium Chloride Phosphates

Stable Strontium. There is no evidence regarding the effect of stable strontium on reproduction, but levels of exposure possible by inhalation or dermal routes are not likely to be harmful. Stable strontium was found to have beneficial effects when it was used in solutions designed for testing the functional capacity of human spermatozoa in vitro (Mortimer 1986 Mortimer et al. 1986). The possible consequences of excess strontium ingestion on reproduction need to be explored. Such experiments should compare the relative toxicity of stable strontium compounds that have different properties and may have different rates of absorption, e.g., strontium chloride, strontium carbonate and strontium phosphate. 

Characteristic properties of endopectate lyases are the high pH optimum, and a requirement for Ca2+ ions in order to maintain catalytic activity. The pH optimum of various endopectate lyases ranges from 8.0 to 9.5 (Refs. 4, 178, 234, 236, 243). Besides activation by Ca2+ ions, the optimal concentration of which is 1 mM,234,236,244 strontium salts were also considered in the case of Bacillus sp. lyase.234 The enzyme from Pseudomonas sp. was also partly activated by magnesium chloride,178 and for the lyase of Clostridium felsineum, salts of other bivalent cations had an activating effect as well.245 (Ethylenedinitrilo)tetraacetic acid completely inactivated all of the lyases mentioned. The activity of endopectate lyase from Pseudomonas was also lessened in the presence of sodium chloride, potassium chloride, and dipotassium hydrogen phosphate (K2HP04). 

There are a number of interferences that can occur in atomic absorption and other flame spectroscopic methods. Anything that decreases the number of neutral atoms in the flame will decrease the absorption signal. Chemical interference is the most commonly encountered example of depression of the absorption signal. Here, the element of interest reacts with an anion in solution or with a gas in the flame to produce a stable compound in the flame. For example, calcium, in the presence of phosphate, will form the stable pyrophosphate molecule. Refractory elements will combine with 0 or OH radicals in the flame to produce stable monoxides and hydroxides. Fortunately, most of these chemical interferences can be avoided by adding an appropriate reagent or by using a hotter flame. The phosphate interferences, for example, can be eliminated by adding 1 % strontium chloride or lanthanum chloride to the solution. The strontium or lanthanum preferentially combines with the phosphate to prevent its reaction with the calcium. Or, EDTA can be added to complex the calcium and prevent its combination with the phosphate. 

Major constituents (greater than 5 mg/L) Minor constituents (O.Ol-lO.Omg/L) Selected trace constituents (less than 0.1 mg/L) Bicarbonate, calcium, carbonic acid, chloride, magnesium, silicon, sodium, sulfate Boron, carbonate, fluoride, iron, nitrate, potassium, strontium Aluminum, arsenic, barium, bromide, cadmium, chromium, cobalt, copper, gold, iodide, lead, Uthium, manganese, molybdenum, nickel, phosphate, radium, selenium, silver, tin, titanium, uranium, vanadium, zinc, zirconium... 

Certain antiseptic and therapeutic agents (such as sodium fluoride, stannous fluoride, strontium chloride, urea, dibasic ammonium phosphate, are used in dentrifrices for their anticarcinogenic, bacteriostatic and bactericidal actions. 

The major inorganic ions in bone mineral are calcium, phosphate and carbonate, with lesser amounts of magnesium, sodium, potassum, chloride, and fluoride66). Traces of iron, copper, lead, manganese, tin, aluminum, strontium, and boron have also been detected67). 

A stock solution of calcium ions was prepared by dissolving 0.1834g of CaCl2.2H20 in 100 ml of distilled water and then further diluting by a factor of 10. From this new solution, three standard solutions were prepared by further dilutions of five, 10 and 20 times, respectively. The unknown sample is itself diluted 25 times. Sufficient strontium chloride was then introduced to eliminate any interference due to phosphate ions. An analytical blank containing the same concentration of strontium was the first solution to be examined by the air/acetylene flame. The results were as follows ... 

By using 5 g. (0.027 mole) of vanadium(V) oxide together with 200 g. (1.26 moles) of strontium chloride and the same basic procedure as for the chloride phosphate, the reaction product,... 

C—F 7.(a) 1.26, non-polar molecule (b) 0.97, polar molecule (c) 1.55, non-polar molecule 3.4 1.(a) potassium chromate (b) ammonium nitrate (c) sodium sulfate (d) strontium phosphate (e) potassium nitrite (f) barium hypochlorite 2.(a) magnesium chloride (b) sodium oxide... 

David (D3) determined calcium in plant materials, employing an air-acetylene flame. After wet-ashing of the samples, magnesium and sulfuric acid were added to overcome effects of anions. It was demonstrated that high concentrations of phosphate, aluminum, and silicate were completely controlled. In soil samples David (D5) determined calcimn by extraction widr ammonium chloride, but used strontium and lanthanum... 

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