Ammonia scavenger
First Claim
1. A particulate magnesium phosphate product which is substantially water insoluble, and when slurried, yields a pH of about 7.4, said product having an empirical composition exclusive of water hydration, as follows:
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space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein when "z" has an assigned value of 1, "x" has a value greater than 1, and about 1.1 to about 1.3, and "y" has a value less than 1 and about 0.4 to about 0.8.
4 Assignments
0 Petitions
Accused Products
Abstract
A new and useful particulate magnesium phosphate product (MGP) and method of use therefor are disclosed for removing ammonia from aqueous solutions, e.g., recirculating dialysate solutions and intragastrointestinal fluids as may result from the hydrolysis of urea. This particulate magnesium phosphate product (MGP) acts as a remarkably effective scavenger wherein under equilibrium conditions only about six (6) grams of the novel product are required to bind the ammonia (more exactly, ammonium ions) liberated from one (1) gram of the urea, a result far superior to traditional zirconium phosphate (ZP) prior art materials which under ideal conditions require about 17-20 grams of ZP per gram of urea. The novel particulate magnesium phosphate product can be exploited in one embodiment as a replacement for the older ZP materials used to remove ammonia produced by enzymatic hydrolysis of urea in recirculating dialysis systems utilizing disposable cartridges. In another embodiment, in a new encapsulated product (comprising a water-insoluble, membranous wall, permeable to urea and/or ammonia and water, while impermeable to urease enzyme, wherein the wall surrounds a core of urease and the novel particulate magnesium phosphate product) is disclosed, which can also be used as an in vivo or in vitro scavenger. This particulate MGP product can also be used for the removal of ammonium ions either produced by enzymatic or non-enzymatic hydrolysis of urea or proteins or amino acids or available as NH4+ from its native source. A new method is also disclosed for the preparation of the novel particulate magnesium phosphate product.
187 Citations
36 Claims
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1. A particulate magnesium phosphate product which is substantially water insoluble, and when slurried, yields a pH of about 7.4, said product having an empirical composition exclusive of water hydration, as follows:
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space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein when "z" has an assigned value of 1, "x" has a value greater than 1, and about 1.1 to about 1.3, and "y" has a value less than 1 and about 0.4 to about 0.8. - View Dependent Claims (2, 3)
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4. A method for scavenging ammonium ions from an aqueous solution, comprising:
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contacting an aqueous solution containing ammonium ions with an ammonium-removing effective amount of a particular magnesium phosphate product, which product is substantially water insoluble, and when slurried yields a pH of about 7.4, said product having an empirical composition exclusive of water of hydration, as follows;
space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein "z" has an assigned value of 1, "x" has a value greater than 1 and of about 1.1 to about 1.3, and "y" has a value less than 1 and of from about 0.4 to about 0.8. - View Dependent Claims (5, 6)
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7. The method for treating an aqueous solution containing ammonium ions, comprising:
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contacting an aqueous solution containing ammonium ions in a recirculating dialysis system with an ammonium-removing effective amount of a particulate magnesium phosphate product which product is substantially water insoluble, and when slurried yields a pH of about 7.4, said product having an empirical composition exclusive of water of hydration, as follows;
space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein "z" has an assigned value of 1, "x" has a value of about 1.1 to about 1.3, and "y" has a value of from about 0.4 to about 0.8. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. A method for the preparation of a particulate magnesium phosphate product which is substantially water insoluble, and when slurried yields a pH of about 7.4, said product having an empirical composition exclusive of water of hydration, as follows:
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space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein when "z" has an assigned value of 1, "x" has a value greater than 1 and from about 1.1 to about 1.3 and "Y" has a value less than 1 and about 0.4 to about 0.8, said method comprising the steps of; (a) mixing and stirring a given amount of magnesium hydroxide with an effective amount of water sufficient only to yield a highly fluid slurry having a pH of about 9.5 to about 10.5; (b) gradually adding and stirring H3 PO4 to said slurry sufficient to lower the pH of said slurry to about 7.4; (c) adding and stirring one or more of the components selected from the group consisting of magnesium hydroxide, magnesium oxide, and phosphoric acid for a time sufficient to stabilize the pH of said slurry to about 7.4 to produce a water insoluble magnesium phosphate product having an empirical formula of;
space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein when "z" has an assigned value of 1, "x" has a value greater than 1 and is from about 1.1 to about 1.3 and "y" has a value less than 1 and from about 0.4 to about 0.8; and (d) separating said magnesium phosphate product from said slurry. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 24, 26, 27, 29, 30, 31, 32, 33, 34, 35)
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23. (b) respectively, are added to water in amounts proportional to the final total quantity.
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25. The method for the preparation of a particulate magnesium phosphate product-containing slurry useful for ammonium scavenging, which product is substantially water insoluble, and when slurried yields a pH of about 7.4, said product having an empirical composition exclusive of water of hydration, as follows:
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space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein when "z" has an assigned value of 1, "x" is greater than 1 and has a value from about 1.1 to about 1.3, and "y" is less than 1 and has a value of about 0.4 to about 0.8, said method comprising steps of; (a) mixing and stirring a given amount of magnesium hydroxide in an effective amount of water sufficient only to yield a highly fluid slurry having a pH of about 9.5 to about 10.5; (b) gradually adding and stirring prosphoric acid to said slurry sufficient to lower the pH of said slurry to about 7.4; (c) stirring one or more of the components selected from the group consisting of magnesium hydroxide, magnesium oxide, and phosphoric acid for a time sufficient to stabilize the pH of said slurry to about 7.4 to product a substantially water insoluble, magnesium phosphate product having an emperical formula of;
space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein when "z" has an assigned value of 1, "x" is greater than 1 and from about 1.1 to about 1.3 and "y" has a value less than 1 and from about 0.4 to about 0.8 in order to form a magnesium phosphate product containing slurry.
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28. A microencapsulated product for removing ammonia and/or urea from aqueous solutions, comprising:
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one or more particles each having a water-insoluble wall permeable to urea, ammonia and water and impermeable to urease enzyme, surrounding a core composition comprising urease and a particulate magnesium phosphate product which is substantially water-insoluble, and when slurried yields a pH of about 7.4, said product having an empirical composition exclusive of water of hydration, as follows;
space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein when "z" has an assigned value of 1, "x" is from about 1.1 to about 1.3 and "y" is from about 0.4 to 0.8.
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36. The method for treating an aqueous solution containing ammonium ions comprising contacting said aqueous solution containing ammonium ions with an ammonium-removing effective amount of a particulate magnesium phosphate product, which product is substantially water insoluble, and when slurried yields a pH of about 7.4, said product having an empirical composition exclusive of water of hydration, as follows:
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space="preserve" listing-type="equation">(Mg).sub.x (H).sub.y (PO.sub.4).sub.zwherein "z" has an assigned value of 1, "x" has a value greater than 1 and of about 1.1 to about 1.2, and "y" has a value less than 1 and from about 0.4 to about 0.8, wherein such contact takes place by means of encapsulating particles containing said particulate magnesium phosphate product.
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Specification