US 11,808,710 B2
Methods and systems for determining an ionic strength of a dilute aqueous solution
Robert H. Byrne, St. Petersburg, FL (US)
Assigned to University of South Florida, Tampa, FL (US)
Filed by University of South Florida, Tampa, FL (US)
Filed on Jun. 24, 2021, as Appl. No. 17/357,075.
Claims priority of provisional application 63/043,885, filed on Jun. 25, 2020.
Prior Publication US 2021/0404972 A1, Dec. 30, 2021
Int. Cl. G01N 21/80 (2006.01); G01N 33/18 (2006.01)
CPC G01N 21/80 (2013.01) [G01N 33/18 (2013.01)] 18 Claims
 
1. A method comprising n stages for determining an ionic strength I of an aqueous sample, wherein the method comprises:
a first of the n stages comprising:
a) adding a pH indicator to a portion of the aqueous sample;
b) adjusting a pH of the portion of the aqueous sample to obtain a pHinitial value;
c) adding an amount of a buffer to the portion of the aqueous sample to obtain a pHfinal;
d) repeating steps a)-c) for n times, until pHinitial is substantially similar to a pHfinal, and is defined as an equilibrium pH0, and wherein
a portion of the aqueous sample in step a) of each subsequent stage is a new portion of the aqueous sample; and
a pHinitial in step b) of each subsequent stage is different from a pHinitial of each preceding stage; and
e) calculating the I value from a ratio of a total alkalinity of the aqueous sample to a total concentration of the buffer At/[Buffer]t, wherein the I value is calculated as a function of a specific dissociation constant K of the buffer; and
wherein a temperature of the portion of the aqueous sample at steps b) and c) is substantially identical.