US 12,253,501 B2
Colorimetric detection and quantitative estimation of peracids using a redox sensitive leuco dye
Ramakrishnan Balasubramanian, Saint Paul, MN (US); and Junzhong Li, Saint Paul, MN (US)
Assigned to ECOLAB USA INC., Saint Paul, MN (US)
Filed by ECOLAB USA INC., Saint Paul, MN (US)
Filed on May 1, 2023, as Appl. No. 18/310,086.
Application 18/310,086 is a continuation of application No. 16/949,739, filed on Nov. 12, 2020, granted, now 11,674,935.
Application 16/949,739 is a continuation of application No. 15/843,168, filed on Dec. 15, 2017, granted, now 10,866,223, issued on Dec. 15, 2020.
Claims priority of provisional application 62/434,554, filed on Dec. 15, 2016.
Prior Publication US 2023/0349873 A1, Nov. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G01N 31/00 (2006.01); G01N 21/78 (2006.01); G01N 31/22 (2006.01); G01N 33/18 (2006.01)
CPC G01N 31/228 (2013.01) [G01N 21/78 (2013.01); G01N 33/18 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A peroxycarboxylic acid quantification composition comprising:
a redox sensitive leuco dye, and
a peroxycarboxylic acid composition;
wherein the peroxycarboxylic acid composition comprises a C1-C22 peroxycarboxylic acid, a C1-C22 carboxylic acid, and a hydrogen peroxide,
wherein the leuco dye selectively reacts with the peroxycarboxylic acid in the peroxycarboxylic acid composition to form a colored species, and the colored species exhibits a stable absorbance within about 20 minutes at a visible light wavelength and the absorbance intensity is linearly proportional to the concentration of the peroxycarboxylic acid of between about 1 ppm and about 100 ppm.