Strontium magnesium phosphate

Since the proteins contain negatively charged groups such as phosphates, side-chain carboxyls, terminal carboxyls, and sulfhydryls, they bind a number of different cations, such as calcium, barium, strontium, magnesium (Dickson and Perkins 1969), copper (Dill and Simmons 1970 Aulakh and Stine 1971), thallium (Sundararajan and Whitney 1969), potassium and sodium (Ho and Waugh 1965), iron (Basch et al. 1974, Demott and Park 1974 Demott and Dincer 1976), cadmium (Roh et al. 1976), and mercury (Roh et al. 1975). 

Inorganic anodic and mixed Cl present water-soluble salts of ammonium, alkali (sodium, potassium), alkaline-earth (calcium, strontium, magnesium, barium) and other (zinc, lead) metals containing active anions in their molecules (nitrates, nitrites, chromates, carbonates, phosphates, molybdates, silicates). ... 

Phosphate, sulfate, and fluoride ions as well as many organic compounds may be determined by means of alkaline earths. For example, calcium has been used for the determination of phosphate and sulfate. Phosphate may also be determined by strontium. Magnesium has been employed for the determination of fluoride and calcium for the determination of glucose. 

Magnesium carbonate Magnesium fluoride Magnesium hydroxide Magnesium phosphate Manganese(II) sulfide Mercury(I) chloride Mercury(II) sulfide Nickel(II) sulfide Silver bromide Silver carbonate Silver chloride Silver chromate Silver iodide Silver sulfate Silver sulfide Strontium carbonate Strontium sulfate Tin(II) sulfide Zinc sulfide... 

A variation of calcium phosphate is the major component of bones and teeth in all vertebrates including humans. These calcium phosphates are usually referred to collectively as biological apatites, which are nonstoichiometric compounds based on pure apatites, Ca5(P04)3X, where X can be fluorine (F), chlorine (Cl), or hydroxyl (OH). (These are called fluoro-, chloro-, and hydroxyapatite, respectively.) In biological apatites the calcium cations can be replaced with varying amounts of strontium, magnesium, sodium, and potassium ions, and the phosphate anions can be replaced with hydrogen phosphates and carbonates. 

The interference due to metals which can exist as anions in the flame is often of a much more serious nature than that due to phosphate and sulphate. For example the addition of 100 p.p.m. of aluminium to a solution containing 5 p.p.m. of calcium causes complete suppression of the calcium emission. However, if an excess of strontium, magnesium or lanthanum is added the calcium emission is completely restored. Fig. 4 shows this in a series of recordings it can be seen that the strontium causes an elevation of the background but the intensity of the CaO band, using a base line... 

Numerous other specialty cements composed of various magnesium, barium, and strontium compounds as siUcates, aluminates, and phosphates, as well as others, are also produced (85). 

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). 

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... 

Admixture incompatibilities - Magnesium sulfate in solution may result in a precipitate formation when mixed with solutions containing Alcohol (in high concentrations) alkali carbonates and bicarbonates alkali hydroxides arsenates barium calcium clindamycin phosphate heavy metals hydrocortisone sodium succinate phosphates polymyxin B sulfate procaine hydrochloride salicylates strontium tartrates. 

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). 

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... 

This is by far the most frequently encountered interference in AAS. Basically, a chemical interference can be defined as anything that prevents or suppresses the formation of ground state atoms in the flame. A common example is the interference produced by aluminium, silicon and phosphorus in the determination of magnesium, calcium, strontium, barium and many other metals. This is due to the formation of aluminates, silicates and phosphates which, in many instances, are refractory in the analytical flame being used. 

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... 

Magnesium, like calcium, is subject to the effect of anions, although to a lesser degree. The most serious interference derives from refractory acidic oxides formed in the flame from a number of elements, particularly aluminum and silicon. The effect of phosphate and sulfate is much less marked than with calcium (Fig. 17), hut if aluminum or silicon is also present in the solutions, magnesium depression is much more severe than with either of these interfering agents alone. These interferences can be overcome by the addition of strontium, lanthanum, or calcium. Leithe and Hofer (L4, L5) showed that magnesium could be determined... 

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