Chlorine Ion in Concrete
Quantification of chlorine ion (Cl-) in hardened concrete is determined by potentiometric titration using chlorine ion electrode and mercury sulphate reference electrode.
After 2 mol/L nitric acid and 30% hydrogen peroxide solution are added to the sample, leave it to cool to room temperature, and add 0.005 mol/L sodium chloride.
Titrate with 0.005 mol/L silver nitrate up to the endpoint, which is the maximum inflexion point on titration curve.
The chlorine ion is calculated from titration volume of silver nitrate