# US 12,222,310 B2 · Magnesium ion selective membranes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,222,310 B2 - Document ID: US12222310B2 - Status: Granted - Kind: B2 - Application number: 18/484,011 - Filed: 2023-10-10 - Published: 2024-02-29 - Granted: 2025-02-11 - Earliest claimed: 2015-02-03 - Assignees: Siemens Healthcare Diagnostics Inc. - Applicants: Siemens Healthcare Diagnostics Inc. - Inventors: John Benco; Robert Bergquist - Web page: https://patentgrep.com/patent/US12222310B2 ## CPC - G01N 27/3335: {the membrane containing at least one organic component (G01N27/3271 takes precedence; aspects concerning the enzyme reagent in enzyme electrodes C12Q1/001)} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract The present invention is directed to membranes, sensors, systems and process for the detection of magnesium ions in protein-containing samples. The novel membranes, sensors, systems, and processes are based upon the discovery that the lipophilicity of the plasticizer (or blend of plasticizers) utilized in the formulation of magnesium ion selective membranes for clinical use is inversely proportional to the sensitivity of the plasticizer(s) and directly proportional to the use life thereof. ## Claims ### Claim 1 A magnesium ion selective membrane that has magnesium selectivity over calcium, the magnesium ion selective membrane comprising: a polymer material; a magnesium-selective material comprising a single ionophore, wherein the ionophore comprises a triamide compound; and a blend of two or more plasticizers, wherein at least one plasticizer comprises a measured log P value of greater than about 5.8 and less than about 12.8, wherein each plasticizer comprises a nitrophenyl group and hydrophobic chain extending therefrom with a structure of: wherein R1 comprises a straight-chain alkyl group having 10 to 14 carbons or comprises a 12-(4-ethyl-phenyl)-dodecyl group. ### Claim 2 (depends on 1) The magnesium ion selective membrane of claim 1, wherein the polymer material comprises a member selected from the group consisting of polyvinyl chloride, polystyrene, polyacrylate, polycarbonate, polyester, polyamide, polyurethane, polyvinyl material, vinyl acetates, and co-polymers of any of the above. ### Claim 3 (depends on 1) The magnesium ion selective membrane of claim 1, wherein the magnesium-selective material comprises an ion exchange material. ### Claim 4 (depends on 3) The magnesium ion selective membrane of claim 3, wherein the ion exchange material comprises potassium tetrakis(4-chlorophenyl)borate. ### Claim 5 (depends on 1) The magnesium ion selective membrane of claim 1, wherein the R1 in the structure of at least one of the plasticizers is a 12-(4-ethyl-phenyl)-dodecyl group. ### Claim 6 (depends on 1) The magnesium ion selective membrane of claim 1, wherein at least one of the plasticizers comprises a measured log P value of about 8. ### Claim 7 (depends on 1) The magnesium ion selective membrane of claim 1, wherein the blend of plasticizers comprises a blend of ETH 8045 and nitro-phenyl octyl ether (NPOE). ### Claim 8 (depends on 7) The magnesium ion selective membrane of claim 7, wherein a weight ratio of ETH 8045 to NPOE is in a range of from about 50:50 to about 66:34. ### Claim 9 (depends on 1) A potentiometric magnesium ion selective sensor configured for determining magnesium ion concentration in biological samples using an automated point-of-care analyzer, the sensor comprising: the magnesium ion selective membrane of claim 1; and a substrate upon which the magnesium ion selective membrane and at least one additional layer are applied, wherein the at least one additional layer is selected from the group consisting of a polymer layer, an electrode layer, a conductor layer, a transducer layer, and combinations thereof. ### Claim 10 (depends on 9) The potentiometric magnesium ion selective sensor of claim 9, wherein the sensor has a clinical use life of at least 25 days. ### Claim 11 (depends on 9) A multi-use cartridge configured for disposal in an automated point-of-care analyzer, the multi-use cartridge comprising the potentiometric magnesium ion selective sensor of claim 9 incorporated therewithin. ### Claim 12 A magnesium ion selective membrane that has magnesium selectivity over calcium, the magnesium ion selective membrane comprising: a polymer material; a magnesium-selective material comprising a single ionophore, wherein the ionophore comprises a triamide compound; and a plasticizer comprising a measured log P value of about 8, wherein the plasticizer comprises a nitrophenyl group and hydrophobic chain extending therefrom with a structure of: wherein R1 comprises a straight-chain alkyl group having 10 to 14 carbons or comprises a 12-(4-ethyl-phenyl)-dodecyl group. ### Claim 13 (depends on 12) The magnesium ion selective membrane of claim 12, wherein the polymer material comprises a member selected from the group consisting of polyvinyl chloride, polystyrene, polyacrylate, polycarbonate, polyester, polyamide, polyurethane, polyvinyl material, vinyl acetates, and co-polymers of any of the above. ### Claim 14 (depends on 12) The magnesium ion selective membrane of claim 12, wherein the R1 in the structure of the plasticizer comprises a straight-chain alkyl group having 12 carbons. ### Claim 15 (depends on 12) The magnesium ion selective membrane of claim 12, wherein the R1 in the structure of the plasticizer is a 12-(4-ethyl-phenyl)-dodecyl group. ### Claim 16 (depends on 12) The magnesium ion selective membrane of claim 12, wherein the magnesium-selective material comprises an ion exchange material, and wherein the ion exchange material comprises potassium tetrakis(4-chlorophenyl)borate. ### Claim 17 (depends on 12) A potentiometric magnesium ion selective sensor configured for determining magnesium ion concentration in biological samples using an automated point-of-care analyzer, comprising: the magnesium ion selective membrane of claim 12; and a substrate upon which the magnesium ion selective membrane and at least one additional layer are applied, wherein the at least one additional layer is selected from the group consisting of a polymer layer, an electrode layer, a conductor layer, a transducer layer, and combinations thereof. ### Claim 18 (depends on 17) The potentiometric magnesium ion selective sensor of claim 17, wherein the sensor has a clinical use life of at least 25 days. ### Claim 19 (depends on 17) A multi-use cartridge configured for disposal in an automated point-of-care analyzer, the multi-use cartridge comprising the potentiometric magnesium ion selective sensor of claim 17 incorporated therewithin.