The Fluorescence Detector

The fluorescence detector is one of the most sensitive LC detectors and for this reason is often used for trace analysis. Unfortunately, although the detector is very sensitive, its response is only linear over a relatively limited concentration range. In fact, the response of the detector can only be assumed to be linear over a concentration range of two orders of magnitude. Unfortunately, the majority of substances do not naturally fluoresce which is a serious disadvantage to this type of detector. It follows, that in many instances fluorescent derivatives must be synthesized to render the substances of interest detectable. There are a number of regents that have been developed specifically for this purpose but derivatizing procedures will be discussed in detail in a later Book. A diagram of the Fluorescence Detector is shown in figure 23.

Figure 23. The Fluorescence Detector