pH measurement pH of 20 mL samples were determined at room temperature and constant agitation using a pH-meter (model 420A, Orion, USA). It was expressed as the negative logarithm of the hydrogen ion concentration in a solution
pH measurementpH of 20 mL samples were determined at room temperature andconstant agitation using a pH-meter (model 420A, Orion, USA). It wasexpressed as the negative logarithm of the hydrogen ion concentrationin a solution