Transfer exactly 25 ml of a 0.1 M arginine to a clean, 50 ml conical flask.

Measure the pH of arginine solution with calibrated pH meter. Record the initial pH.

Obtain 20 ml of 1 M HCl, slowly add 0.2 mL HCl and mix the solution by swirling. Wait for the pH value to stabilize on the pH meter and record the pH.

Again, add 0.2 ml HCl while swirling and record the pH.

Continue the titration until the solution reaches a pH 1.5 ± 0.1