The renaissance of liquid chromatography took place in the late 1960's and early 1970's. The first edition of this book published in 1977 described the detectors that were available at that time and which provided a performance matching that of the contemporary equipment with which they were associated. It is interesting to note that the most popular detectors then (the UV detector, the refractometer detector, the fluorescence detector and the electrical conductivity detector) are still the most commonly used detectors nearly a decade later. Detector design, however, has changed very significantly over the intervening years. Modern high efficiency columns provide very narrow peaks and very fast separations, and thus the physical design of the detectors had to change to meet these new challenges. In 1977, there was little real understanding of the important role played by the detector in the overall function of the chromatographic system and although some of the factors were pointed out in the first edition of this book, in retrospect they appeared to be little understood. This second edition gives an entirely new presentation of the subject of liquid chromatography detectors.