The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 04, 1995
Filed:
Jul. 05, 1994
Jay M Johnson, Dayton, OH (US);
Robert B Spokane, Bellbrook, OH (US);
The Yellow Springs Instrument Company, Inc., Yellow Springs, OH (US);
Abstract
Improved methods and compositions are provided to inhibit interference from formaldehyde in polarographic analytic methods. In the enzymatic oxidation of methanol to hydrogen peroxide and formaldehyde, formaldehyde serves as an interfering agent in systems where the oxygen consumed or the hydrogen peroxide produced is polarographically measured. To inhibit this interference, an amine-containing formaldehyde scavenger is added to the test system. Preferably, the scavenger comprises a polyalkyleneimine such as polyethyleneimine having a molecular weight of between about 200-1,000,000 amu. The invention is particularly well-suited for use in polarographic analytical apparatus wherein laminated membrane type enzyme electrodes are used to perform amperometric measurement with alcohol oxidase enzyme used as the oxidoreductase enzyme. Determination of methanol concentration in liquid samples can be used to assess the amount of L-Asp-L-Phe-methyl ester (aspartame-TM) present in diet soft drink samples that have been hydrolyzed with the enzyme Bovine alpha-chymotrypsin to yield L-Asp-L-phe and methanol.