Free acidity measurement – A review

• A literature review of free acidity measurements in the presence of hydrolysable ions has been done.
• The review has been classified with respect to the method used, complexant employed.
• Importance has been attributed to measurements involving actinide solutions.

Free acidity is an important parameter especially in the presence of hydrolysable ions. Several methods have been developed for the determination of free acidity, attributing due importance to the accuracy and the precision of the measurement with the aim of the easiness of the methodology as well as post-measurement recovery in mind. This review covers important methods for the determination of free acidity with emphasis on actinide containing solutions, reported in the literature over the past several decades classifying them into different categories.