Electrochemical Detector:

Electrochemical detectors have been found to be especially useful for polar mobile phase. These detectors provide considerable selectivity because only a few components in a complex mixture are likely to be electoractive. Sensitivisity is very high, in many cases a picomole or less can be detected. Phenols and aromatic amines of biochemical interest are the most important class of compounds where electrochemical detectors can be used.

Differential refractometers are the universal type of detectors except when refractive index of data sample component is same as that of the mobile phase. However, these have limitations of having poor detection sensitivity, lack of selectivity and extreme sensitivity to temperature and flow changes. It is essential to maintain cell temperature within 0.001ºC. Response time is also somewhat large, about 2 sec. Photograph of an Agilent 1100 (USA) HPLC set up is shown in Figure. Besides, there are several other manufacturers such as Perkin-Elmer Corporation (USA), Beckman Instruments (USA), Shimadzu Scientific Instruments (Japan), Bio-Rad Laboratories (USA), Hewlett-Packard Co (USA) wherefrom or through their representatives the instrument or its accessories can be procured.