Book excerpt: Process analytical chemistry (PAC) can be defined as the technology of obtaining quantitative and qualitative information about a chemical process in order to control or optimise its performance. This highly practical book provides an up-to-date introduction to the field with a special emphasis placed on industrial processes. Edited by representatives from one of the world's leading chemical companies and centres of excellence for research into the subject, the book is written by a transatlantic team of authors who provide a global perspective.