Analytical Chemistry–3 provides information pertinent to the development of analytical chemistry. This book discusses the significant role of analytical chemistry in the progress of the chemical industry. Organized into nine chapters, this book begins with an overview of the contribution of analytical chemistry in the development as well as in process control of the industrial chemistry. This text then presents a brief history concerning the development of analytical chemistry in Romania. Other chapters consider the general problem of utilizing gradients in chromatography. This book discusses as well the developments in the determination of some common anions and describes the separation of anions of the same species. The final chapter deals with the classification of enrichment methods according to the type of sample for which they are to be used. This book is a valuable resource for chemists, analytical chemists, and pharmaceutical chemists. Teachers, scientists, researchers, and specialists in Romanian school of chemistry will also find this book useful.