US 11,726,070 B2
Method and kit for detecting diesel exhaust fluid in fuel
Ronald Schornstein, Mountain Lakes, NJ (US); and Samuel D'Arcangelis, Randolph, NJ (US)
Assigned to Acustrip Company, Inc., Denville, NJ (US)
Filed by Acustrip Company, Inc., Denville, NJ (US)
Filed on Nov. 10, 2020, as Appl. No. 17/93,840.
Prior Publication US 2022/0146477 A1, May 12, 2022
Int. Cl. G01N 31/22 (2006.01); G01N 33/22 (2006.01)
CPC G01N 31/22 (2013.01) [G01N 33/22 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method for detecting diesel exhaust fluid (DEF) in fuel, the method comprising:
obtaining a fuel sample to be tested;
combining the fuel sample with a buffered urease solution for making a test solution, the buffered urease solution having a pH of about 6.8 to about 7.8;
agitating the test solution;
allowing the test solution to separate into two or more layers, including an aqueous layer, and developing urea from DEF into ammonia;
adjusting a pH of the aqueous layer to greater than or equal to about 11;
contacting a reagent strip with the aqueous layer; and
developing a color change of the aqueous layer to detect a presence of ammonia.