||Biological electrodes specific for phosphate and nitrite ions /
Guilbault, George G.
||New Orleans Univ., La.;Environmental Research Lab., Athens, Ga.
|| Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency ; Available through the National Technical Information Service,
||EPA 600/4-76-034; EPA-R-800359
Water quality bioassay
Water analysis ;
Inorganic phosphates ;
Water pollution ;
Chemical analysis ;
Ion exchanging ;
Biological detection ;
Alkaline phosphatases ;
Selective ion electrodes ;
Water pollution detection ;
Immobilized enzymes ;
||OCSPP Chemical Library/Washington,DC
||Research Triangle Park Library/RTP, NC
||Region 10 Library/Seattle,WA
||Some EPA libraries have a fiche copy filed under the call number shown.
||v, 8 pages ; 28 cm.
Biological electrodes have been developed for the selective analysis of phosphate and nitrate ions at micro-levels. A phosphate electrode was constructed by using two enzymes, alkaline phosphatase and glucose oxidase which were immobilized and mounted on the surface of the Platinum electrode. The competitive inhibition of phosphate ion on alkaline phosphatase slows down the hydrolysis of glucose-6-phosphate to glucose which is subsequently used by glucose oxidase as a substrate in the presence of molecular oxygen. The phosphate ion concentration in the reaction mixture was found to be proportional to the oxygen consumption. The assay of nitrite was accomplished with the use of nitrite reductase which catalyzes the reduction of nitrite into ammonia. Nitrite in the range of .0001 M-.01 M could be accurately determined with either soluble or immobilized enzyme using an air-gap electrode as sensor. Preparations of benzidine phosphate and hexammino cobalt nitrate in silicone rubber for liquid ion exchange and triphenyltin electrode have been attempted and results obtained were unsatisfactory due to their poor selectivity. This report was submitted in fulfillment of R 800359-02 by University of New Orleans under the sponsorship of the Environmental Protection Agency. Work was completed as date of 12-31-75.
"EPA-600/4-76-034." Includes bibliographical references (page 7).