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:
Oct. 13, 2015
Filed:
Aug. 22, 2006
Applicants:
Darrell Green, Cleveland, GB;
Andrew West, Cleveland, GB;
Inventors:
Darrell Green, Cleveland, GB;
Andrew West, Cleveland, GB;
Assignee:
Johnson Matthey PLC, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N 37/00 (2006.01); C01C 1/08 (2006.01); F01N 3/20 (2006.01); G01N 21/64 (2006.01); G01N 21/78 (2006.01);
U.S. Cl.
CPC ...
C01C 1/086 (2013.01); F01N 3/2066 (2013.01); G01N 21/643 (2013.01); G01N 21/78 (2013.01); F01N 2610/00 (2013.01); F01N 2610/02 (2013.01); Y02T 10/24 (2013.01); Y10T 436/13 (2015.01);
Abstract
A method of tracing an aqueous liquid, particularly an aqueous urea used for addition to a selective catalytic reduction system to remove NOx from diesel exhaust includes adding a tracer comprising a pre-determined amount of a phenol to the liquid. The liquid can subsequently be identified by reacting a sample with a reagent containing a predetermined amount of 4-aminoantipyrine in the presence of an initiating compound such that the reaction between the reagent and a phenol in the liquid produces a chromophore and measuring the absorbance of the resulting solution of the chromophore.