Peroxycarboxylic acid compositions suitable for inline optical or conductivity monitoring
Peracid stable fluorescent active compounds in highly acidic, equilibrium peroxycarboxylic acid sanitizing compositions are disclosed as having improved fluorescent stability allowing for monitoring of peroxycarboxylic acid concentration by conductivity and/or optical sensors. Beneficially, the compositions are also low odor and low/no VOC dual functioning acid wash and sanitizing compositions.
1. An equilibrium peracid composition comprising: a C 1 -C 22 peroxycarboxylic acid;
a C 1 -C 22 carboxylic acid;
hydrogen peroxide; and
an aryl sulfonate fluorescent active compound, wherein the fluorescent active compound is stable in the equilibrium peracid composition for monitoring peroxycarboxylic acid concentration by an optical sensor, and provides a fluorescent emission equal to or greater than 0.01 SU in an aqueous solution and that is proportional to peroxycarboxylic acid concentration as measured by an optical sensor when the concentrated composition is diluted to from about 0.05 wt-% to about 0.25 wt-% in water,
wherein the fluorescent active compound is sodium xylene sulfonate, toluene sulfonate, alkyl diphenyl oxide disulfonate, naphthalene sulfonate, alkyl naphthalene sulfonate, naphthalene disulfonate or sodium cumene sulfonate.
2. The composition of claim 1 , wherein the C 1 -C 22 peroxycarboxylic acid comprises from about 1 wt-% to about 40 wt-%, the C 1 -C 22 carboxylic acid comprises from about 1 wt-% to about 80 wt-%, the hydrogen peroxide comprises from about 1 wt-% to about 80 wt-%, and the fluorescent active compound comprises from about 0.001 wt-% to about 10 wt-%.
3. The composition of claim 1 , further comprising at least one additional agent selected from the group consisting of an acidulant, a hydrotrope, a solvent, a stabilizing agent, an anionic surfactant, an metal salt defoaming agent, and combinations thereof.
4. The composition of claim 1 , wherein the C 1 -C 22 peroxycarboxylic acid is a C 2 -C 20 peroxycarboxylic acid and wherein the C 1 -C 22 carboxylic acid is a C 2 -C 20 carboxylic acid.
5. The composition of claim 4 , wherein the peroxycarboxylic acid is peroxyacetic acid, peroxyoctanoic acid and/or peroxysulfonated oleic acid, and wherein the carboxylic acid is acetic acid, octanoic acid, sulfonated oleic acid or a combinations of the same.
6. The composition of claim 1 , wherein the pH of the use solution is below about 4.
7. The composition of claim 1 , further comprising an alkaline metal defoaming agent, an anionic surfactant, and a peroxycarboxylic acid stabilizing agent, wherein the stabilizing agent is a picolinic acid or a compound having the following Formula (IA):
wherein R 1 is OH or —NR 1a R 1b , wherein R 1a and R 1b are independently hydrogen or (C 1 -C 6 )alkyl; wherein R 2 is OH or —NR 2a R 2b , wherein R 2a and R 2b are independently hydrogen or (C 1 -C 6 )alkyl; wherein each R 3 is independently (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl or (C 2 -C 6 )alkynyl; and n is a number from zero to 3; or a salt thereof;
or a compound having the following Formula (IB):
wherein R 1 is OH or —NR 1a R 1b , wherein R 1a and R 1b are independently hydrogen or (C 1 -C 6 )alkyl; wherein R 2 is OH or —NR 2a R 2b , wherein R 2a and R 2b are independently hydrogen or (C 1 -C 6 )alkyl; wherein each R 3 is independently (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl or (C 2 -C 6 )alkynyl; and n is a number from zero to 3; or a salt thereof, wherein the stabilizing agent delays or prevents the peroxycarboxylic acid from exceeding its self-accelerating decomposition temperature (SADT).