ANALYTICAL ELEMENT AND METHOD FOR DETERMINATION OF MAGNESIUM IONS

• Main Authors: TONER, JOHN L, MAUCK, JOHN C, SMITH-LEWIS, MARGARET J
• Format: Patent
• Language: English; French
• Published: 15.10.1991
• Edition: 5
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

ANALYTICAL ELEMENT AND METHOD FOR DETERMINATION OF MAGNESIUM IONS An analytical element is used to determine magnesium ions at a pH of from about 8.5 to about 11. This element comprises an absorbent carrier material containing a 1,5-bis(2-hydroxyphenyl)-3-cyanoformazan compound which is substituted in at least one of the 3-, 4- and 5-positions of either phenyl moiety. The substituents are chosen such that their cumulative Hammet-sigma value is greater than about 0.23, provided that none of the substituents is carboxy. The assay is carried out in the presence of a calcium ion chelating agent and a suitable buffer. In preferred embodiments, the cyanoformazan is incorporated in the element in such a manner so as to be isolated from protein molecules which may be encountered in the assay.