A monograph on flow injection analysis, which has gradually evolved into a powerful technique for substituting tedious manual separation procedures by producing stronger contacts between chemistry and the analytical instrument. This work is intended to be used as a source reference book for the research analytical chemist and as a laboratory handbook for the routine analyst who wish to automate or/and improve the performance of their instrumental analytical procedures, particularly when dealing with samples with complex matrices, such as those frequently encountered in environmental, agricultural and clinical applications. It is composed of nine chapters with a brief introduction on the basic principles and instrumentation, followed by separate chapters on liquid-liquid extraction, sorption, gas-liquid separation, dialysis, and precipitation. Finally, two separate chapters are devoted to environmental and agricultural aplications and clinical and pharmaceutical applications.