Improved magnesium ion selective membranes

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 lipophilcity 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.

1 . A magnesium ion selective membrane comprising:
 a polymer material;   a magnesium-selective material; and   a plasticizer comprising a measured log P value of greater than about 5.8 and less than about 12.8.   
     
     
         2 . The 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. 
     
     
         3 . The membrane in  claim 1 , wherein the plasticizer comprises a blend of two or more plasticizers. 
     
     
         4 . The membrane in  claim 1 , wherein the plasticizer comprises a measured log P value of about 7 to about 9. 
     
     
         5 . The membrane of  claim 4 , wherein the plasticizer comprises a measured log P value of about 8. 
     
     
         6 . The membrane of  claim 1 , wherein the magnesium-selective material comprises an ion exchange material. 
     
     
         7 . The membrane of  claim 6 , wherein the ion exchange material comprises potassium tetrakis(4-chlorophenyl)borate. 
     
     
         8 . The membrane in  claim 1 , wherein the magnesium-selective material comprises an ionophore. 
     
     
         9 . The membrane of  claim 8 , wherein the ionophore comprises a triamide compound. 
     
     
         10 . A magnesium ion selective electrode comprising the membrane in  claim 1 . 
     
     
         11 . A magnesium ion selective sensor comprising a membrane in  claim 1 . 
     
     
         12 . An array of sensors comprising:
 the sensor of  claim 11  for determining an amount of magnesium in a protein-containing sample; and   at least one additional sensor for determining an amount of additional target analyte in the protein-containing sample.   
     
     
         13 . The array of  claim 12 , wherein the at least one additional sensor is configured for analysis of a member selected from the group consisting of pH, carbon dioxide partial pressure, oxygen partial pressure, sodium, potassium, calcium, chloride, hematocrit, hemoglobin, glucose, lactate, bilirubin, and CO-oximeter fractions. 
     
     
         14 . A process for analyzing a protein-based sample for magnesium comprising:
 a sensor including a magnesium ion selective membrane that comprises:   a polymer material;   a magnesium-selective material; and   a plasticizer comprising a measured log P value of greater than 5.8 and less than 12.8,   introducing a protein-containing sample with the sensor; and   determining a presence of magnesium in the sample after the contacting.   
     
     
         15 . The process of  claim 14 , wherein the protein-containing sample comprises whole blood. 
     
     
         16 . The process in  claim 14 , 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. 
     
     
         17 . The process of  claim 14 , wherein the plasticizer comprises a blend of two or more plasticizers and the blend of plasticizers comprises a blend of ETH 8045 and nitro-phenyl octyl ether (NPOE). 
     
     
         18 . The process in  claim 14 , further comprising:
 further comprising providing one or more additional sensors for detection of a presence of an additional analyte or property in the sample selected from the group consisting of pH, carbon dioxide partial pressure, oxygen partial pressure, sodium, potassium, calcium, chloride, hematocrit, hemoglobin, glucose, lactate, bilirubin, and CO-oximeter fractions; and   detecting the presence of the additional analyte or property in the sample.