Laser-based detectors in chromatographic analysis.

Advances in detection technology have been a vital part of the development of microscale chromatographic techniques. Separation techniques such as microbore liquid chromatography impose severe constraints on the permissible volume of detector cells. The use of lasers to construct a new generation of chromatographic detectors has satisfied the need for low volume detection and high sensitivity. The unique properties of laser radiation have been used to advantage in designing new approaches to the detection of optical absorbance through fluorescence emission and thermal effects. New approaches to monitoring refractive index changes and optical rotation have also been developed. Together, the combination of microscale-separation techniques and highly sensitive detection provide a powerful tool for analysing small quantities of samples. Yet, there are practical limitations arising from the cost and complexity of much of the instrumentation reported to date, as well as the difficulties of preparing small samples for analysis which have limited the wide-scale application of these methods to solve practical problems. Recent advances in laser technology such as the advent of diode lasers may be useful in overcoming some of these limitations.