Infrared (IR) spectrometric detection in liquid chromatography (LC) can provide useful information which is not amenable to other detectors. In the past, the range of real life analytical applications was limited due to the low sensitivity of IR detection and difficulties in on-line measurements arising from the dominating absorption of most of commonly used mobile phase systems. This book describes instrumental developments as well as chemometric advances improving the feasibility of LC-IR on-line coupling, giving rise to exciting new possibilities for the use of vibrational detection systems in LC. Latest innovations on the field of on-line LC-IR under isocratic conditions and new chemometric methods for background compensation in gradient systems are discussed in detail. Furthermore recent instrumental advances concerning IR sources and miniaturized devices are introduced. Technological advances are demonstrated by means of diverse examples of applications. This book should be especially useful for analytical chemists, including newcomers and experts on LC-IR on-line coupling, as theoretical backgrounds as well as practical issues are taken into account.