The performance of some liquid phase flow-through detectors

Miniaturization of flow-through analytical systems such as flow injection analysis and liquid chromatography is necessary to achieve higher rates of sample throughput and smaller absolute detection limits. During this miniaturization, however, it is essential to preserve the concentration detection limits of the devices used. Some principles for liquid phase flow-through detection, u.v.-visible absorption photometry, fluorimetry and electrochemical detection, are discussed from this point of view. It appears that, although technical difficulties will be large, there are good prospects of detecting concentrations of about 1 ng ml^?1, while keeping the peak broaadening down to values of about 1 nl.